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.

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gi 149048770   2 SDMYLICRLQPRSFT-INFCQQECLKCEWMDLESLARTKHTTPITSRVARLLLY 54
Cdd:cd04670   77 SDLYFVCRLRPLSDEeIKICPEEIAEAKWMPLEEYLKQPNVSQINKLVAKLLLE 130

Antisense Basic Fibroblast Growth Factor; Antisense Basic Fibroblast Growth Factor (ASFGF2; EC 3.6.1.-), also known as nucleoside diphosphate-linked moiety X)) motif 6/Nudt6, and similar proteins including peroxisomal coenzyme A diphosphatase/Nudt7 and mitochondrial coenzyme A diphosphatase/Nudt8. The Nudt6 gene overlaps and lies on the opposite strand from FGF2 gene, and is thought to be the FGF2 antisense gene. The two genes are independently transcribed, and their expression shows an inverse relationship, suggesting that this antisense transcript may regulate FGF2 expression. This gene has also been shown to have hormone-regulatory and antiproliferative actions in the pituitary that are independent of FGF2 expression. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. 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.

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                 ....*....|....*....|....*....|....*....|....*....|....
gi 149048770   2 SDMYLICRLQPRSFT-INFCQQECLKCEWMDLESLARTKHTTPITSRVARLLLY 54
Cdd:cd04670   77 SDLYFVCRLRPLSDEeIKICPEEIAEAKWMPLEEYLKQPNVSQINKLVAKLLLE 130

Antisense Basic Fibroblast Growth Factor; Antisense Basic Fibroblast Growth Factor (ASFGF2; EC 3.6.1.-), also known as nucleoside diphosphate-linked moiety X)) motif 6/Nudt6, and similar proteins including peroxisomal coenzyme A diphosphatase/Nudt7 and mitochondrial coenzyme A diphosphatase/Nudt8. The Nudt6 gene overlaps and lies on the opposite strand from FGF2 gene, and is thought to be the FGF2 antisense gene. The two genes are independently transcribed, and their expression shows an inverse relationship, suggesting that this antisense transcript may regulate FGF2 expression. This gene has also been shown to have hormone-regulatory and antiproliferative actions in the pituitary that are independent of FGF2 expression. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. 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
                 ....*....|....*....|....*....|....*....|....*....|....
gi 149048770   2 SDMYLICRLQPRSFT-INFCQQECLKCEWMDLESLARTKHTTPITSRVARLLLY 54
Cdd:cd04670   77 SDLYFVCRLRPLSDEeIKICPEEIAEAKWMPLEEYLKQPNVSQINKLVAKLLLE 130