8-oxo-dGTP diphosphatase MutT;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   1 MKILQIAVGIIRNQHNEIFITQRAADAHMANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPDRHI 80
Cdd:PRK10776   1 MKKLQIAVGIIRNPNNEIFITRRAADAHMAGKWEFPGGKIEAGETPEQALIRELQEEVGITVQHATLFEKLEYEFPDRHI 80

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*....
gi 489108885  81 TLWFWLVESWEGEPWGKEGQPAQWIAQYALNAEDFPPANAPVIEKLITG 129
Cdd:PRK10776  81 TLWFWLVESWEGEPWGKEGQPGRWVSQVALNADEFPPANEPIIAKLKAL 129

8-oxo-dGTP diphosphatase MutT;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   1 MKILQIAVGIIRNQHNEIFITQRAADAHMANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPDRHI 80
Cdd:PRK10776   1 MKKLQIAVGIIRNPNNEIFITRRAADAHMAGKWEFPGGKIEAGETPEQALIRELQEEVGITVQHATLFEKLEYEFPDRHI 80

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*....
gi 489108885  81 TLWFWLVESWEGEPWGKEGQPAQWIAQYALNAEDFPPANAPVIEKLITG 129
Cdd:PRK10776  81 TLWFWLVESWEGEPWGKEGQPGRWVSQVALNADEFPPANEPIIAKLKAL 129

MutT pyrophosphohydrolase; The MutT pyrophosphohydrolase is a prototypical NUDIX hydrolase that catalyzes the hydrolysis of nucleoside and deoxynucleoside triphosphates (NTPs and dNTPs) by substitution at a beta-phosphorus to yield a nucleotide monophosphate (NMP) and inorganic pyrophosphate (PPi). This enzyme requires two divalent cations for activity; one coordinates the phosphoryl groups of the NTP/dNTP substrate, and the other coordinates to the enzyme. It also contains the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as metal binding and catalytic site. MutT pyrophosphohydrolase is important in preventing errors in DNA replication by hydrolyzing mutagenic nucleotides such as 8-oxo-dGTP (a product of oxidative damage), which can mispair with template adenine during DNA replication, to guanine nucleotides.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   4 LQIAVGIIRNQhNEIFITQRAADAHMANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPDRHITLW 83
Cdd:cd03425    1 IEVVAAIIVDD-GRVLIAQRPEGKHLAGLWEFPGGKVEPGETPEQALVRELREELGIEVEVGEPLGTVEHDYPDFHVRLH 79

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....
gi 489108885  84 FWLVESWEGEPWGKEGQPAQWIAQYALNAEDFPPANAPVIEKLI 127
Cdd:cd03425   80 VYLCTLWSGEPQLLEHQELRWVTPEELDDLDWLPADIPIVEALL 123

NUDIX domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885    7 AVGIIRNQHNEIFITQRAADAHMANKLEFPGGKIEAGETPEQALIRelQEEIGITPTKSSLFEKlEYQFPDRHITLWFWL 86
Cdd:pfam14815   1 AVLVIRNGDGRVLLRKRPEKGLLGGLWEFPGGKVEPGETLEEALAR--LEELGIEVEVLEPGTV-KHVFTHFRLTLHVYL 77

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 489108885   87 VESWEGEPWgkEGQPAQWIAQYALNAEDFPPANAPVIEK 125
Cdd:pfam14815  78 VREVEGEEE--PQQELRWVTPEELDKYALPAAVRKILEA 114

8-oxo-dGTP diphosphatase MutT;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   1 MKILQIAVGIIRNQHNEIFITQRAADAHMANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPDRHI 80
Cdd:PRK10776   1 MKKLQIAVGIIRNPNNEIFITRRAADAHMAGKWEFPGGKIEAGETPEQALIRELQEEVGITVQHATLFEKLEYEFPDRHI 80

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*....
gi 489108885  81 TLWFWLVESWEGEPWGKEGQPAQWIAQYALNAEDFPPANAPVIEKLITG 129
Cdd:PRK10776  81 TLWFWLVESWEGEPWGKEGQPGRWVSQVALNADEFPPANEPIIAKLKAL 129

Nudix family hydrolase;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   1 MKILQIAVGIIRNQHNEIFITQRAADAHMANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPDRHI 80
Cdd:PRK08999   2 MKRIHVAAGVIRDADGRILLARRPEGKHQGGLWEFPGGKVEPGETVEQALARELQEELGIEVTAARPLITVRHDYPDKRV 81

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|...
gi 489108885  81 TLWFWLVESWEGEPWGKEGQPAQWIAQYALNAEDFPPANAPVI 123
Cdd:PRK08999  82 RLDVRRVTAWQGEPHGREGQPLAWVAPDELAVYPFPPANQPIV 124

ADP-ribose pyrophosphatase YjhB, NUDIX family [Nucleotide transport and metabolism];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   7 AVGIIRNQHNEIFITQRAaDAHMANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPDRHITLWFwL 86
Cdd:COG1051    9 VDAVIFRKDGRVLLVRRA-DEPGKGLWALPGGKVEPGETPEEAALRELREETGLEVEVLELLGVFDHPDRGHVVSVAF-L 86

                         90       100       110
                 ....*....|....*....|....*....|....*....
gi 489108885  87 VESWEGEPW-GKEGQPAQWIAQYALNAEDFPPANAPVIE 124
Cdd:COG1051   87 AEVLSGEPRaDDEIDEARWFPLDELPELAFTPADHEILE 125

NUDIX hydrolase superfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   6 IAVGIIRNQHNEIFITQRAaDAHMANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPD--RHITLW 83
Cdd:cd02883    2 AVGAVVFDDEGRVLLVRRS-DGPGPGGWELPGGGVEPGETPEEAAVREVREETGLDVEVLRLLGVYEFPDPDegRHVVVL 80

                         90       100
                 ....*....|....*....|....*
gi 489108885  84 FWLVESWEGEPW---GKEGQPAQWI 105
Cdd:cd02883   81 VFLARVVGGEPPpldDEEISEVRWV 105

NUDIX domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885    4 LQIAVGI-IRNQHNEIFITQRAaDAHMANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQ------FP 76
Cdd:pfam00293   2 RRVAVGVvLLNEKGRVLLVRRS-KKPFPGWWSLPGGKVEPGETPEEAARRELEEETGLEPELLELLGSLHYLapfdgrFP 80

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|...
gi 489108885   77 DRHITLwFWLVESWEGEP---WGKEGQPAQWIAQYALNAEDFPPANAPVIEKL 126
Cdd:pfam00293  81 DEHEIL-YVFLAEVEGELepdPDGEVEEVRWVPLEELLLLKLAPGDRKLLPWL 132

MutT homolog-1 (MTH1); MutT homolog-1 (MTH1; EC 3.6.1.- ), also called nucleoside diphosphate-linked moiety X)) motif 1 (Nudt1), is a member of the NUDIX hydrolase superfamily. MTH1, the mammalian counterpart of MutT, hydrolyzes oxidized purine nucleoside triphosphates, such as 8-oxo-dGTP and 2-hydroxy-ATP, to monophosphates, thereby preventing the incorporation of such oxygen radicals during replication. This is an important step in the repair mechanism in genomic and mitochondrial DNA. Like other members of the NUDIX family, it requires a divalent cation, such as Mg2+ or Mn2+, for activity, and contain the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as a metal binding and catalytic site. MTH1 is predominantly localized in the cytoplasm and mitochondria. Structurally, this enzyme adopts a similar fold to MutT despite low sequence similarity outside the conserved NUDIX motif. The most distinctive structural difference between MutT and MTH1 is the presence of a beta-hairpin, which is absent in MutT. This results in a much deeper and narrower substrate binding pocket. Mechanistically, MTH1 contains dual specificity for nucleotides that contain 2-OH-adenine bases and those that contain 8-oxo-guanine bases.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 489108885  30 ANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPDRHITLW---FwLVESWEGEP 94
Cdd:cd03427   26 AGKWNGFGGKVEPGETIEEAAVRELEEEAGLTATELEKVGRLKFEFPDDPEAMDvhvF-RADSWTGEP 92

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   6 IAVGIIRNQHNEIFITQ-RAADAHMankleFPGGKIEAGETPEQALIRELQEEIGITPTKSSL-----FEKLEYQFPDRH 79
Cdd:cd04690    2 VKAAVIIIKDGRLLLVRkRGTDAFY-----LPGGKREPGETPLQALVRELKEELGLDLDPDSLrflgtFEAPAANEPGTT 76

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|
gi 489108885  80 ITLWFWLVEsWEGEPwgkegQPAQWIAQYA-LNAEDFPPAN-APVIEKLI 127
Cdd:cd04690   77 VRMTCFTAD-YDGEP-----QPAAEIEELRwLDPADPDDDRlAPLLREIV 120

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   5 QIAVGIIRNQHNEIFITQRAADAHMA--NKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPDRHITL 82
Cdd:cd18882    2 EVAIAILYDDRGKVLLQLRDDKPGIPypGYWGLFGGHLEPGETPEEAIRRELEEEIGYEPGEFRFFLLYTEDDGEDRIRH 81

                 ...
gi 489108885  83 WFW 85
Cdd:cd18882   82 VFH 84

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 489108885   6 IAVGIIRNQHNEIFITQRAAD-AHMANKLEF-PGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQF 75
Cdd:cd04693   31 VVHVWIFNSDGEILIQQRSPDkKGFPGMWEAsTGGSVLAGETSLEAAIRELKEELGIDLDADELRPILTIRF 102

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   3 ILQIAVGIIRNQHNEIFITQRAaDAHmanKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLF-----EKLEYQFP- 76
Cdd:cd04677   11 ILVGAAVIILNEQGRILLQKRT-DTG---DWGLPGGAMELGESLEETARREVFEETGLTVEELELLgvysgKDLYYTYPn 86

                         90       100
                 ....*....|....*....|.
gi 489108885  77 -DR--HITLWFwLVESWEGEP 94
Cdd:cd04677   87 gDEvyNVTAVY-LVRDVSGEL 106

MutT homolog 2; MutT Homolog 2 (MTH2; EC 3.6.1.9), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 15/Nudt15, may catalyze the hydrolysis of nucleoside diphosphates, triphosphates including dGTP, dTTP, dCTP, their oxidized forms like 8-oxo-dGTP, and prodrug thiopurine derivatives 6-thio-dGTP and 6-thio-GTP. MTH2 may also play a role in DNA synthesis and cell cycle progression by stabilizing PCNA. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885   6 IAVG-IIRNQHNEIFITQRAaDAHMANKLEFPGGKIEAGETPEQALIRELQEEIG--ITPTK-----SSLFEKleyqfPD 77
Cdd:cd04678    3 VGVGvIVLNDDGKVLLGRRK-GSHGAGTWALPGGHLEFGESFEECAAREVLEETGleIRNVRfltvtNDVFEE-----EG 76

                         90
                 ....*....|....*...
gi 489108885  78 RH-ITLWFwLVESWEGEP 94
Cdd:cd04678   77 KHyVTIFV-LAEVDDGEP 93

NUDIX domain family found in Deinococcus radiodurans, and similar proteins; Deinococcus radiodurans protein DR_0079 is one of 21 NUDIX hydrolases that it encodes, and it has been observed to have a marked preference for cytosine ribonucleoside 5'-diphosphate (CDP) and cytosine ribonucleoside 5'-triphosphate (CTP), and for their corresponding deoxyribose nucleotides, dCDP and dCTP, to a lesser degree. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 489108885  11 IRNQHNEIFITQRAADahmanKLEFP-------GGKIEAGETPEQALIRELQEEIGITPTK 64
Cdd:cd24154    9 LINSQGQLWIPRRTAD-----KRIFPlaldmsvGGHVSSGETYEQAFVRELQEELNLDLDQ 64

ADP-ribose pyrophosphatase, UDP-glucose pyrophosphatase, and similar proteins; ADP-ribose pyrophosphatase (ADPRase) ( NUDIX (Nucleoside diphosphate-linked moiety X)) motif 5; Nudt5) catalyzes the hydrolysis of ADP-ribose and a variety of additional ADP-sugar conjugates to AMP and ribose-5-phosphate. In humans, there are four distinct ADPRase activities, three putative cytosolic enzymes (ADPRase-I, -II, and -Mn) and a single mitochondrial enzyme (ADPRase-m). Human ADPRase-II is also referred to as NUDT5. It lacks the N-terminal target sequence unique to mitochondrial ADPRase. The different cytosolic types are distinguished by their specificities for substrate and specific requirement for metal ions. NUDT5 forms a homodimer. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site. In addition to the NUDIX motif, there are additional conserved amino acid residues, distal from the signature sequence, that correlate with substrate specificity. UDP-glucose pyrophosphatase (UGPPase) (EC 3.6.1.45; also known as nucleoside diphosphate-linked moiety X)) motif 14; Nudt14) hydrolyzes the pyrophosphate of the nucleoside diphosphate sugar to generate glucose-1-P and UMP. In mammals, UDP-glucose is the glucosyl donor for the synthesis of the storage polysaccharide glycogen. UGPPase, as a regulator of UDP-glucose, could play a regulatory role, but it has been shown to prefer ADP-ribose over UDP-glucose. Like other members of the NUDIX hydrolase superfamily, it requires a divalent cation, such as Mg2+, for its activity. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 489108885  33 LEFPGGKIEAGETPEQALIRELQEEIGITPTKsslFEKLEYQFPD 77
Cdd:cd03424   31 LELPAGKIDPGEDPEEAARRELEEETGYTAGD---LELLGSFYPS 72

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 489108885  10 IIRNQHNEIFITQRAAdahmaNKLEFPG-------GKIEAGETPEQALIRELQEEIGITPTksslFEKLEYQFP 76
Cdd:cd04692   33 LVNPEEGRLLLQKRSA-----NKDDFPGlwdisaaGHIDAGETYEEAAVRELEEELGLTVS----PEDLIFLGV 97

coenzyme A pyrophosphatase and similar proteins; Coenzyme A pyrophosphatase (CoAse; EC 3.6.1.1), also called nucleoside diphosphate-linked moiety X)) motif 7, is a member of the NUDIX hydrolase superfamily, functions to catalyze the elimination of oxidized inactive CoA, which can inhibit CoA-utilizing enzymes. The need of CoAses mainly arises under conditions of oxidative stress. CoAse has a conserved NUDIX fold and requires a single divalent cation for catalysis. In addition to a signature NUDIX motif G[X5]E[X7]REUXEEXGU, where U is Ile, Leu, or Val, CoAse contains an additional motif upstream called the NuCoA motif (LLTXT(SA)X3RX3GX3FPGG) which is postulated to be involved in CoA recognition. CoA plays a central role in lipid metabolism. It is involved in the initial steps of fatty acid sythesis in the cytosol, in the oxidation of fatty acids and the citric acid cycle in the mitochondria, and in the oxidation of long-chain fatty acids in peroxisomes. CoA has the important role of activating fatty acids for further modification into key biological signalling molecules.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 489108885   7 AVGII---RNQHNEIFITQRAAD-----AHMAnkleFPGGKIEAG-ETPEQALIRELQEEIGITPTKSSLFEKLEYQF 75
Cdd:cd03426    4 AVLIPlveGDGELHVLLTKRASHlrshpGQIA----FPGGKREPGdESPVETALRETEEEIGLPPESVEVLGRLDPLY 77

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 489108885   6 IAVGIIRNQHNEIFITQRAADAHmankLEFPGGKIEAGETPEQALIRELQEEIGITPT 63
Cdd:cd18876    2 AAGALFTDAAGRVLLVKPTYKDG----WELPGGVVEAGESPLQAARREVREELGLDVP 55

nucleoside triphosphatase YtkD; The functional assignment to the proteins of this family is contentious, with papers disagreeing in both interpretation and enzyme assay results. This protein belongs to the nudix family and shares some sequence identity with E. coli MutT but appears not to be functionally interchangeable with it. [DNA metabolism, DNA replication, recombination, and repair]

                          10        20        30
                  ....*....|....*....|....*....|..
gi 489108885   28 HMANKLEFPGGKIEAGETPEQALIRELQEEIG 59
Cdd:TIGR02705  42 HKRRGLEFPGGKVEPGETSKEAAIREVMEETG 73

ADP-ribose pyrophosphatase; ADP-ribose pyrophosphatase (ADPRase) (also known as NUDIX (Nucleoside diphosphate-linked moiety X)) motif 5; Nudt5) catalyzes the hydrolysis of ADP-ribose and a variety of additional ADP-sugar conjugates to AMP and ribose-5-phosphate. In humans, there are four distinct ADPRase activities, three putative cytosolic enzymes (ADPRase-I, -II, and -Mn) and a single mitochondrial enzyme (ADPRase-m). Human ADPRase-II is also referred to as NUDT5. It lacks the N-terminal target sequence unique to mitochondrial ADPRase. The different cytosolic types are distinguished by their specificities for substrate and specific requirement for metal ions. NUDT5 forms a homodimer. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site. In addition to the NUDIX motif, there are additional conserved amino acid residues, distal from the signature sequence, that correlate with substrate specificity.

                         10        20
                 ....*....|....*....|....*..
gi 489108885  33 LEFPGGKIEAGETPEQALIRELQEEIG 59
Cdd:cd18888   35 IEFPAGLVDPGESPEQAALRELKEETG 61

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20
                 ....*....|....*....|....*....
gi 489108885  35 FPGGKIEAGETPEQALIRELQEEIGITPT 63
Cdd:cd04667   25 LPGGKIEPGESPLEAAIRELKEETGLAAL 53

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 489108885  35 FPGGKIEAGETPEQALIRELQEEIGITPT-KSSLFE--KLEYQFPDRHITLwfWLVESWEGEPW 95
Cdd:cd04680   27 LPGGGVDKGETAEEAARRELREEAGVVLTgPPRLFGvyFNRRVSPRDHVAL--YRVREFEQTEP 88

adenosine nucleotide hydrolase NudE; Provisional

                         10        20
                 ....*....|....*....|....*..
gi 489108885  33 LEFPGGKIEAGETPEQALIRELQEEIG 59
Cdd:PRK11762  76 LGFPKGLIDPGETPLEAANRELKEEVG 102

Adp-ribose pyrophosphatase (ADPRase) found in Thermus thermophilus, and similar proteins; ADP-ribose pyrophosphatase (ADPRase) such as found in extreme thermophile Thermus thermophilus (TtADPRase) catalyzes the hydrolysis of ADPR to AMP and ribose 5'-phosphate in the presence of Mg2+ and Zn2+ ions. In humans, there are four distinct ADPRase activities, three putative cytosolic enzymes (ADPRase-I, -II, and -Mn) and a single mitochondrial enzyme (ADPRase-m). Human ADPRase-II is also referred to as NUDT5. It lacks the N-terminal target sequence unique to mitochondrial ADPRase. The different cytosolic types are distinguished by their specificities for substrate and specific requirement for metal ions. NUDT5 forms a homodimer. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site. In addition to the NUDIX motif, there are additional conserved amino acid residues, distal from the signature sequence, that correlate with substrate specificity. UDP-glucose pyrophosphatase (UGPPase) (EC 3.6.1.45; also known as nucleoside diphosphate-linked moiety X)) motif 14; Nudt14) hydrolyzes the pyrophosphate of the nucleoside diphosphate sugar to generate glucose-1-P and UMP. In mammals, UDP-glucose is the glucosyl donor for the synthesis of the storage polysaccharide glycogen. UGPPase, as a regulator of UDP-glucose, could play a regulatory role, but it has been shown to prefer ADP-ribose over UDP-glucose. Like other members of the NUDIX hydrolase superfamily, it requires a divalent cation, such as Mg2+, for its activity. It also contains a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 489108885   7 AVGIIRNQHNEI-FITQ--RAADAHmanKLEFPGGKIEAGETPEQALIRELQEEIGIT 61
Cdd:cd24160   23 AVAVLALREGRMlFVRQmrPAVGAA---TLEIPAGLIDPGETPEEAARRELAEETGLS 77

dihydroneopterin hydrolase; DHNTP pyrophosphatase (DHNTPase) catalyzes the hydrolysis of dihydroneopterin triphosphate (DHNTP) to dihydroneopterin monophosphate (DHNMP) and pyrophosphate,the second step in the pterin branch of the folate synthesis pathway in bacteria. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 489108885  10 IIRNQHNEIFITQRAADAhmaNKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLF-EKLEYQFPDRH 79
Cdd:cd04664    8 YRKDEEGEVLLLKRTDDG---GFWQSVTGGIEDGETPWQAALRELKEETGLDPLELQLIdLNVSNFYEIFD 75

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885  10 IIRNQHNEIFITQRAADAhmANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLfeKLEYQFPD----RHITLWFW 85
Cdd:cd18875    8 MIYDGEDRVLVLDRVKKD--WGGYTFPGGHVEPGESFVDSVIREVKEETGLTIKNPEL--CGIKQWINpdgeRYIVFLYK 83

                         90
                 ....*....|....*..
gi 489108885  86 -------LVESWEGEPW 95
Cdd:cd18875   84 tdhfsgeLLSSEEGELF 100

MutT homolog-1 and similar proteins; MutT homolog-1 (MTH1), also known as NUDIX (nucleoside diphosphate-linked moiety X)) motif 1/Nudt1, is a member of the NUDIX hydrolase superfamily. MTH1, the mammalian counterpart of MutT, hydrolyzes oxidized purine nucleoside triphosphates, such as 8-oxo-dGTP and 2-hydroxy-ATP, to monophosphates, thereby preventing the incorporation of such oxygen radicals during replication. This is an important step in the repair mechanism in genomic and mitochondrial DNA. Like other members of the NUDIX family, it requires a divalent cation, such as Mg2+ or Mn2+, for activity, and contain the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as a metal binding and catalytic site. MTH1 is predominantly localized in the cytoplasm and mitochondria. Structurally, this enzyme adopts a similar fold to MutT despite low sequence similarity outside the conserved NUDIX motif. The most distinctive structural difference between MutT and MTH1 is the presence of a beta-hairpin, which is absent in MutT. This results in a much deeper and narrower substrate binding pocket. Mechanistically, MTH1 contains dual specificity for nucleotides that contain 2-OH-adenine bases and those that contain 8-oxo-guanine bases.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 489108885  36 PGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEYQFPD--RHITLWFWLVESWEGEP 94
Cdd:cd04679   32 PGGKVDWLETVEDAVRREILEELGLEIELTRLLCVVDQIDAAdgEHWVAPVYLAEIFSGEP 92

diadenosine hexaphosphate (Ap6A) hydrolase; Diadenosine hexaphosphate (Ap6A) hydrolase is a member of the NUDIX hydrolase superfamily. Ap6A hydrolase specifically hydrolyzes diadenosine polyphosphates, but not ATP or diadenosine triphosphate, and it generates ATP as the product. Ap6A, the most preferred substrate, hydrolyzes to produce two ATP molecules, which is a novel hydrolysis mode for Ap6A. These results indicate that Ap6A hydrolase is a diadenosine polyphosphate hydrolase. It requires the presence of a divalent cation, such as Mn2+, Mg2+, Zn2+, and Co2+, for activity. Members of the NUDIX hydrolase superfamily are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site.

                         10        20
                 ....*....|....*....|....*..
gi 489108885  35 FPGGKIEAGETPEQALIRELQEEIGIT 61
Cdd:cd03673   31 LPKGKLEPGETPEEAAVREVEEETGLR 57

diadenosine tetraphosphate; Diadenosine tetraphosphate (Ap4A; EC 3.6.1.17), also called NUDIX (nucleoside diphosphate-linked moiety X)) motif 2/Nudt2, is a member of the NUDIX hydrolase superfamily. Ap4A hydrolases are well represented in a variety of prokaryotic and eukaryotic organisms. Phylogenetic analysis reveals two distinct subgroups where plant enzymes fall into one subfamily and fungi/animals/archaea enzymes, represented by this subfamily, fall into another. Bacterial enzymes are found in both subfamilies. Ap4A is a potential by-product of aminoacyl tRNA synthesis, and accumulation of Ap4A has been implicated in a range of biological events, such as DNA replication, cellular differentiation, heat shock, metabolic stress, and apoptosis. Ap4A hydrolase cleaves Ap4A asymmetrically into ATP and AMP. It is important in the invasive properties of bacteria and thus presents a potential target for inhibition of such invasive bacteria. Besides the signature NUDIX motif (G[X5]E[X7]REUXEEXGU, where U is Ile, Leu, or Val) that functions as a metal binding and catalytic site, and a required divalent cation, Ap4A hydrolase is structurally similar to the other members of the NUDIX hydrolase superfamily with some degree of variation. Several regions in the sequences are poorly defined and substrate and metal binding sites are only predicted based on kinetic studies.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885  10 IIRNQHNEI--FITQRAADAHmankLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLF--EKLEYQF-PDRHITLWF 84
Cdd:cd03428    9 IYRRDNGEIefLLLQHSYGGH----WDFPKGHVEPGESELETALRETKEETGLTVDDLPPGfrETLTYSFkEGVEKTVVY 84

                 ....
gi 489108885  85 WLVE 88
Cdd:cd03428   85 FLAE 88

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 489108885  22 QRAADAHMANKLEFPGGKIEAGETPEQALIRELQEEIGITP 62
Cdd:cd18877   38 HRAWWTHQGGTWALPGGARDSGETPEAAALRETEEETGLDA 78

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 489108885   9 GIIRNQHNEIFITQRAADAHMAnkleFPGGKIEAGETPEQALIRELQEEIGI 60
Cdd:cd04676   22 AVILNEDGRILLQRKGGLGLWS----LPAGAIEPGEHPAEAVIREVREETGL 69

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20
                 ....*....|....*....|....*.
gi 489108885  36 PGGKIEAGETPEQALIRELQEEIGIT 61
Cdd:cd18874   31 PGGKVEWGETLEEALKREVKEETGLD 56

NUDIX family Ndx2; NUDIX family protein Ndx2 found in Thermus thermophilus has ADP-ribose pyrophosphatase (ADPRase) as well as flavin adenine dinucleotide (FAD) activity. ADPRase (EC 3.6.1.13) catalyzes the hydrolysis of ADP-ribose to AMP and ribose-5-P. Like other members of the NUDIX hydrolase superfamily of enzymes, it is thought to require a divalent cation, such as Mg2+, for its activity. It also contains a 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V) which functions as a metal binding site/catalytic site. In addition to the NUDIX motif, there are additional conserved amino acid residues, distal from the signature sequence, that correlate with substrate specificity.Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of NUDIX hydrolases include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20
                 ....*....|....*....|....*....
gi 489108885  33 LEFPGGKIEAGETPEQALIRELQEEIGIT 61
Cdd:cd24161   32 WEIPAGGWPEGEDPEEAARRELREETGLR 60

bifunctional NMN adenylyltransferase/ADP-ribose pyrophosphatase and similar proteins; Bacterial NadM-Nudix is a bifunctional enzyme containing a nicotinamide mononucleotide (NMN) adenylyltransferase (NMNAT) and an ADP-ribose pyrophosphatase (ADPRase) domain. NMNAT was initially identified as an NAD+ synthase that catalyzes the reversible conversion of NMN to NAD+ in the final step of both the de novo biosynthesis and salvage pathways in most organisms across all three kingdoms of life ADPRase is a member of the NUDIX family proteins, catalyzes the metal-induced and concerted general acid-base hydrolysis of ADP ribose (ADPR) into AMP and ribose-5'-phosphate (R5P). Additional members in this cd include bacterial transcriptional regulator, NrtR, which represses the transcription of NAD biosynthetic genes in vitro and adenosine diphosphate ribose (ADPR), as well as NadQ, a NUDIX-like ATP-responsive regulator of NAD biosynthesis. Members of the NUDIX hydrolase superfamily catalyze the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belong to this superfamily requires a divalent cation, such as Mg2+ or Mn2+ for their activity and contain a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, U=I, L or V) which functions as metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance _ "house-cleaning" enzymes. Substrate specificity is used to define families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required.

                         10        20
                 ....*....|....*....|....*...
gi 489108885  35 FPGGKIEAGETPEQALIRELQEEIGITP 62
Cdd:cd18873   35 LPGGFVREDETLEDAARRELREETGLKD 62

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489108885  30 ANKLEFPGGKIEAGETPEQALIRELQEEIGITPTKSSLFEKLEY---QFPDRhiTLWFwLVESWEGEP-----WGKEGQP 101
Cdd:cd04682   27 PNLWDLPGGGREGDETPFACVLRELREELGLALPEDRLVWERVYpsnHNPGR--QSWF-FVARLPADEvdairFGDEGQE 103

                         90
                 ....*....|....
gi 489108885 102 AQWIAqyalnAEDF 115
Cdd:cd04682  104 WALMP-----VDDF 112

NADH pyrophosphatase; NADH pyrophosphatase, also known as NUDIX (nucleoside diphosphate linked moiety X)) motif 13/Nudt13, is thought to have NADH pyrophosphatase activity, be involved in NADH metabolic process and NADP catabolic process, catalyzing the cleavage of NADH into reduced nicotinamide mononucleotide (NMNH) and AMP, and located in mitochondrion. Like other members of the NUDIX family, it requires a divalent cation, such as Mg2+ or Mn2+, for activity. Members of this family are also recognized by the NUDIX motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as a metal binding and catalytic site. A block of 8 conserved amino acids downstream of the NUDIX motif is thought to give NADH pyrophosphatase its specificity for NADH. NADH pyrophosphatase forms a dimer.

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                 ....*....|....*....|....
gi 489108885  38 GKIEAGETPEQALIRELQEEIGIT 61
Cdd:cd03429   33 GFVEPGETLEEAVRREVKEEVGLR 56

dihydroneopterin triphosphate pyrophosphatase; Provisional

                         10        20
                 ....*....|....*....|...
gi 489108885  38 GKIEAGETPEQALIRELQEEIGI 60
Cdd:PRK09438  38 GSLEEGETPAQTAIREVKEETGI 60

uncharacterized NUDIX hydrolase subfamily; NUDIX hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of NUDIX hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the NUDIX hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.

                         10        20
                 ....*....|....*....|....*
gi 489108885  38 GKIEAGETPEQALIRELQEEIGITP 62
Cdd:cd18884   40 GFLEAGESPEEAVLREVKEELGLDG 64