Sortase domain found in class A sortases; Class A sortases are membrane-bound cysteine transpeptidases distributed in Gram-positive bacteria (mainly present in Firmicutes). They perform a housekeeping role in the cell as members of this group are capable of anchoring a large number of functionally distinct surface proteins containing a cell wall sorting signal to an amino group located on the bacterial cell wall. They do so by catalyzing a transpeptidation reaction in which the surface protein substrate is cleaved at a conserved cell wall-sorting signal (Class A sortases recognize a canonical LPXTG motif, X can be any amino acid), and covalently linked to peptidoglycan for display on the bacterial surface. The prototypical sortase A protein from Staphylococcus aureus (named Sa-SrtA) cleaves the amide bond between threonine and glycine residues of the canonical LPXTG motif in a wide range of protein substrates with diverse functions that can promote bacterial adhesion, nutrient acquisition, host cell invasion, and immune evasion. Next, it catalyzes a transpeptidation reaction by which the proteins are covalently linked to the peptidoglycan precursor lipid II. SrtA is therefore affects the ability of a pathogen to establish successful infection. SrtA contains an N-terminal hydrophobic segment, a linker region and an extra-cellular C-terminal catalytic domain. The hydrophobic segment functions as both a signal peptide for secretion and a stop-transfer signal for membrane anchoring. The catalytic domain contains the catalytic TLXTC signature sequence where X is usually a valine, isoleucine or a threonine. The gene encoding SrtA is generally not located in the same gene cluster as its substrates while the gene encoding SrtB is usually clustered in the same locus as its substrate.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496  85 VLGKVAVPSVGIALPVMKGVSEATMAQGGGTMKPDQKMGaDNNYALAGHSFTN---IFLPLENVKVGDMVYLTDLQNVYS 161
Cdd:cd06165    3 VIGAIAIPSVGINLPIFKGLSNENLLVGAGTMKPNQKMG-KGNYVLAGHNMGDgglLFSPLQNLKKGDKIYLTDLKKVYE 81

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*.
gi 510996496 162 YRVNVKKSIAPEEVKVIDDVPGHKMVTLITCD---QTVRRWCVQGE 204
Cdd:cd06165   82 YKVTSKKVVDPTDVDVLDDTKGKPLLTLITCDdptDTTKRIVVQGE 127

Sortase domain found in class A sortases; Class A sortases are membrane-bound cysteine transpeptidases distributed in Gram-positive bacteria (mainly present in Firmicutes). They perform a housekeeping role in the cell as members of this group are capable of anchoring a large number of functionally distinct surface proteins containing a cell wall sorting signal to an amino group located on the bacterial cell wall. They do so by catalyzing a transpeptidation reaction in which the surface protein substrate is cleaved at a conserved cell wall-sorting signal (Class A sortases recognize a canonical LPXTG motif, X can be any amino acid), and covalently linked to peptidoglycan for display on the bacterial surface. The prototypical sortase A protein from Staphylococcus aureus (named Sa-SrtA) cleaves the amide bond between threonine and glycine residues of the canonical LPXTG motif in a wide range of protein substrates with diverse functions that can promote bacterial adhesion, nutrient acquisition, host cell invasion, and immune evasion. Next, it catalyzes a transpeptidation reaction by which the proteins are covalently linked to the peptidoglycan precursor lipid II. SrtA is therefore affects the ability of a pathogen to establish successful infection. SrtA contains an N-terminal hydrophobic segment, a linker region and an extra-cellular C-terminal catalytic domain. The hydrophobic segment functions as both a signal peptide for secretion and a stop-transfer signal for membrane anchoring. The catalytic domain contains the catalytic TLXTC signature sequence where X is usually a valine, isoleucine or a threonine. The gene encoding SrtA is generally not located in the same gene cluster as its substrates while the gene encoding SrtB is usually clustered in the same locus as its substrate.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496  85 VLGKVAVPSVGIALPVMKGVSEATMAQGGGTMKPDQKMGaDNNYALAGHSFTN---IFLPLENVKVGDMVYLTDLQNVYS 161
Cdd:cd06165    3 VIGAIAIPSVGINLPIFKGLSNENLLVGAGTMKPNQKMG-KGNYVLAGHNMGDgglLFSPLQNLKKGDKIYLTDLKKVYE 81

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*.
gi 510996496 162 YRVNVKKSIAPEEVKVIDDVPGHKMVTLITCD---QTVRRWCVQGE 204
Cdd:cd06165   82 YKVTSKKVVDPTDVDVLDDTKGKPLLTLITCDdptDTTKRIVVQGE 127

Sortase domain; The founder member of this family is S. aureus sortase, a transpeptidase that attaches surface proteins by the threonine of an LPXTG motif to the cell wall.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496   89 VAVPSVGIALPVMKGVSEATMAQGGGTMKPDQKMGADNNYALAGHSFTN--IFLPLENVKVGDMVYLTDLQNVYSYRVNV 166
Cdd:pfam04203   1 LEIPAIGVDAPVLEGTSGEVLKYGVGHYDGTAMPGEKGNFVLAGHRMGGgtVFARLDKLKKGDKIYVTTDGKTYTYRVTS 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|.
gi 510996496  167 KKSIAPEEVKVIDDVPGHKMVTLITCD--QTVRRWCVQGEL 205
Cdd:pfam04203  81 VEVVDPDDVSVLDPTPGDPILTLITCTppSYTKRLVVYAKL 121

class C sortase;

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496  81 GDVIVLGKVAVPSVGIALPVMKGVSEATMAQG----GGTMKPdqkMGADNNYA-LAGHS-------FTNiflpLENVKVG 148
Cdd:NF033745  86 NETGVMGYIEIPKINVKLPIYHGTSEEVLQKGaghlEGTSLP---VGGKGTHSvITGHRglpsatlFTD----LDKLKKG 158

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....
gi 510996496 149 DMVYLTDLQNVYSYRVNVKKSIAPEEVKVIDDVPGHKMVTLITC 192
Cdd:NF033745 159 DKFYIHVLGETLAYKVDQIKVVLPDDTDKLKIVPGKDLVTLLTC 202

Sortase domain found in class A sortases; Class A sortases are membrane-bound cysteine transpeptidases distributed in Gram-positive bacteria (mainly present in Firmicutes). They perform a housekeeping role in the cell as members of this group are capable of anchoring a large number of functionally distinct surface proteins containing a cell wall sorting signal to an amino group located on the bacterial cell wall. They do so by catalyzing a transpeptidation reaction in which the surface protein substrate is cleaved at a conserved cell wall-sorting signal (Class A sortases recognize a canonical LPXTG motif, X can be any amino acid), and covalently linked to peptidoglycan for display on the bacterial surface. The prototypical sortase A protein from Staphylococcus aureus (named Sa-SrtA) cleaves the amide bond between threonine and glycine residues of the canonical LPXTG motif in a wide range of protein substrates with diverse functions that can promote bacterial adhesion, nutrient acquisition, host cell invasion, and immune evasion. Next, it catalyzes a transpeptidation reaction by which the proteins are covalently linked to the peptidoglycan precursor lipid II. SrtA is therefore affects the ability of a pathogen to establish successful infection. SrtA contains an N-terminal hydrophobic segment, a linker region and an extra-cellular C-terminal catalytic domain. The hydrophobic segment functions as both a signal peptide for secretion and a stop-transfer signal for membrane anchoring. The catalytic domain contains the catalytic TLXTC signature sequence where X is usually a valine, isoleucine or a threonine. The gene encoding SrtA is generally not located in the same gene cluster as its substrates while the gene encoding SrtB is usually clustered in the same locus as its substrate.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496  85 VLGKVAVPSVGIALPVMKGVSEATMAQGGGTMKPDQKMGaDNNYALAGHSFTN---IFLPLENVKVGDMVYLTDLQNVYS 161
Cdd:cd06165    3 VIGAIAIPSVGINLPIFKGLSNENLLVGAGTMKPNQKMG-KGNYVLAGHNMGDgglLFSPLQNLKKGDKIYLTDLKKVYE 81

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*.
gi 510996496 162 YRVNVKKSIAPEEVKVIDDVPGHKMVTLITCD---QTVRRWCVQGE 204
Cdd:cd06165   82 YKVTSKKVVDPTDVDVLDDTKGKPLLTLITCDdptDTTKRIVVQGE 127

Sortase domain found in subfamily 2 of the class D family of sortases; Class D sortases are cysteine transpeptidases distributed in Gram-positive bacteria (mainly present in Firmicutes). They anchor surface proteins bearing a cell wall sorting signal to peptidoglycans of the bacterial cell wall envelope, which is responsible for spore formation under anaerobic conditions. This involves a transpeptidation reaction in which the surface protein substrate is cleaved at the cell wall sorting signal and covalently linked to peptidoglycan for display on the bacterial surface. The prototypical subfamily 2 of class D sortase from Clostridium perfringens (named Cp-SrtD) recognizes the LPQTGS signal motif for transpeptidation. Its catalytic activity is in a metal cation- and temperature- dependent manner. The presence of magnesium appears to enhance Cp-SrtD catalysis towards the LPQTGS signal motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496  85 VLGKVAVPSVGIALPVMKGVSEATMAQGGGTMKPDQKMGADNNYALAGH---SFTNIFLPLENVKVGDMVYLTDLQNVYS 161
Cdd:cd06166    3 VIGILEIPKIDLKLPILEGATEENLKYGVGHFEGTAMPGEGGNFAIAGHrsyTYGRFFNRLDELKIGDEIIVTTKNGTYT 82

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*
gi 510996496 162 YRVNVKKSIAPEEVKVIDDVPGHKMVTLITCDQTV--RRWCVQGE 204
Cdd:cd06166   83 YKVTEIFIVEPTDVSVLDPTEGKKEITLITCTPINptHRLIVKAE 127

Sortase domain; Sortases are cysteine transpeptidases, mainly found in Gram-positive bacteria, which either anchor surface proteins to peptidoglycans of the bacterial cell wall envelope or link proteins together to form pili by working alone, or in concert with other enzymes. They do so by catalyzing a transpeptidation reaction in which the surface protein substrate is cleaved at a conserved cell wall sorting signal and covalently linked to peptidoglycan for display on the bacterial surface. Sortases are grouped into different classes based on sequence, membrane topology, genomic positioning, and cleavage site preference. The different classes are called class A to F sortases. Most Gram-positive bacteria contain more than one sortase and it is thought that the different sortases attach different surface protein classes. The typical eight-stranded beta-barrel fold is observed in all known sortases, along with the conserved catalytic triad consisting of cysteine, histidine and arginine residues. Some sortases contain an N-terminal signal peptide only and the C-terminus serves as a membrane anchor, which represents a type I membrane topology, with the N-terminal enzymatic portion projecting towards the bacterial surface and the C-terminal end residing in the cytoplasm. Other sortases adopt a type II membrane topology, with the N-terminal hydrophobic segment inside the cytoplasm and the C-terminal enzymatic portion located across the plasma membrane. The N-terminus either functions as both a signal peptide for secretion and a stop-transfer signal for membrane anchoring. Sortases are also present in some Gram-negative and Archaebacterial species, but the functions of these enzymes are unknown.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496  85 VLGKVAVPSVGIALPVMKGVSEATMAQGGGTMKPDQkMGADNNYALAGHSFTNI--FLPLENVKVGDMVYLTDLQNVYSY 162
Cdd:cd00004    3 YIGILEIPKINLKLPVLSGTSYENLKIAPGRYYGSA-LGENGNIVIAGHNGNGGshFGNLKKLKKGDEIYLTDKGKTYTY 81

                         90       100       110
                 ....*....|....*....|....*....|.
gi 510996496 163 RVNVKKSIAPEEVKVIDDVPGHKMVTLITCD 193
Cdd:cd00004   82 KVTEIEEVEPTDVEVILVTSGDKDLTLITCT 112

Sortase domain found in subfamily 1 of the class D family of sortases; Class D sortases are cysteine transpeptidases distributed in Gram-positive bacteria (mainly present in Firmicutes). The prototypical subfamily 1 of class D sortase from Bacillus anthracis (named Ba-SrtC) covalently attaches proteins bearing a noncanonical LPNTA sorting signal, such as the BasH and BasI proteins, to the peptidoglycan of the cell wall that facilitate sporulation. BasH is exclusively anchored to the forespore cell wall envelope, while BasI is attached to the diaminopimelic acid moiety of the peptidoglycan of predivisional cells. Ba-SrtC lacks the N-terminal signal peptide and membrane anchor. The family also includes many class D sortase homologs from Gram-negative bacteria, but the functions of these enzymes are unknown.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496  85 VLGKVAVPSVGIALPVMKGVSEATMAQGGGTMKPDQKMGADNNYALAGHSFTNiFLPLENVKVGDMVYLTDLQNVYSYRV 164
Cdd:cd05828    3 PVARLSIPRLGLDLPVLEGTSGEALAFGPGHLPGSALPGEGGNVVIAGHRDTH-FRFLKDLKVGDEITLETSGGTYTYRV 81

                         90       100
                 ....*....|....*....|....*...
gi 510996496 165 nVKKSIAPEEVKVIDDVPGHKMVTLITC 192
Cdd:cd05828   82 -TETRIVDADDTSVLLPTDEETLTLVTC 108

Sortase domain found in the class E family of sortases; Class E sortases are membrane-bound cysteine transpeptidases distributed in Gram-positive bacteria (mainly present in Actinobacteria). Genes encoding class A and E sortases are never found in the same organism, and similar to class A sortases, the genes encoding class E sortases are not positioned adjacent to genes encoding potential protein substrates, suggesting a housekeeping sortase function of class E sortases in some high G + C Gram-positive bacteria. Similar to class A sortase, class E sortases are capable of anchoring a large number of functionally distinct surface proteins containing a cell wall sorting signal to an amino group located on the bacterial cell wall. They recognize an LAXTG sorting signal, instead of the canonical LPXTG motif processed by class A sortases. The prototypical class E sortase from Corynebacterium diphtheria (named Cd-SrtF) is a non-polymerization sortase that is not required for pilus polymerization, and proceeds to complete the assembly process by anchoring the polymer to the cell wall peptidoglycan. Moreover, in Streptomyces coelicolor, one or both of Staphylococcus aureus SrtA homologs may function as class E sortase responsible for the cell wall anchoring of the long chaplin proteins (ChpA-C) containing an LAXTG sorting signal, which presumably mediate aerial hyphae formation. The family also includes some class E sortase homologs from Gram-negative and Archaebacterial species, but the functions of these enzymes are unknown.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496  85 VLGKVAVPSV-GIALPVMKGVSEATMAQGGGTMKPDQKMGADNNYALAGH--SFTNIFLPLENVKVGDMVYLTDLQNVYS 161
Cdd:cd05830    3 AFAVLYIPRFiDLDRPVVEGTSEVLLRRGVGHYPGTALPGEVGNFAIAGHrtTYGAPFRDLDELRPGDPIVVETAGGWYV 82

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|...
gi 510996496 162 YRVNVKKSIAPEEVKVIDDVPGH-------KMVTLITCD---QTVRRWCVQGE 204
Cdd:cd05830   83 YRVTSTEIVSPDDVEVLAPVPGQpgappgrRLLTLTTCHppgSSAERLIVHAE 135

Sortase domain found in the class F family of sortases; Class F sortases are mainly present in Actinobacteria, Chlorobacteria and Firmicutes. Their functions are largely unknown.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 510996496  89 VAVPSVGIALPVMK-GVseatmaQGGGTM----KPDQ--------KMGADNNYALAGHSFTN----IFLPLENVKVGDMV 151
Cdd:cd05829    7 LSIPAIGVDAPVVPvGL------DADGAMpvppDPDRagwyrggpAPGEAGTAVIAGHVDSGggpgVFARLGDLRPGDEV 80

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|
gi 510996496 152 YLTDLQ-NVYSYRVNVKKSIAPEEV--KVIDDVPGHKMVTLITCDQTVRR 198
Cdd:cd05829   81 TVTRADgTTATFRVTSVETYPKDDLptDEVFGPTGPPRLRLITCGGAFDR 130