Xenobiotic acyltransferase (XAT): The XAT class of hexapeptide acyltransferases is composed of a large number of microbial enzymes that catalyze the CoA-dependent acetylation of a variety of hydroxyl-bearing acceptors such as chloramphenicol and streptogramin, among others. Members of this class of enzymes include Enterococcus faecium streptogramin A acetyltransferase and Pseudomonas aeruginosa chloramphenicol acetyltransferase. They contain repeated copies of a six-residue hexapeptide repeat sequence motif (X-[STAV]-X-[LIV]-[GAED]-X) and adopt a left-handed parallel beta helix (LbH) structure. The active enzyme is a trimer with CoA and substrate binding sites at the interface of two separate LbH subunits. XATs are implicated in inactivating xenobiotics leading to xenobiotic resistance in patients.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489550389  46 YLMPDRDDV--DKLVIGSFCSIGSGAAFIMAGNqgHRAEWASTFPFHFMHEEPAFAGAVNGYQPAGDTLIGHDVWIGTEA 123
Cdd:cd03349    9 YGSGPDCDVggDKLSIGKFCSIAPGVKIGLGGN--HPTDWVSTYPFYIFGGEWEDDAKFDDWPSKGDVIIGNDVWIGHGA 86

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 489550389 124 MFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRKRFSDGDIQNLLEMAWWDWP 182
Cdd:cd03349   87 TILPGVTIGDGAVIAAGAVVTKDVPPYAIVGGNPAKVIRYRFDEETIERLLALKWWDWP 145

Xenobiotic acyltransferase (XAT): The XAT class of hexapeptide acyltransferases is composed of a large number of microbial enzymes that catalyze the CoA-dependent acetylation of a variety of hydroxyl-bearing acceptors such as chloramphenicol and streptogramin, among others. Members of this class of enzymes include Enterococcus faecium streptogramin A acetyltransferase and Pseudomonas aeruginosa chloramphenicol acetyltransferase. They contain repeated copies of a six-residue hexapeptide repeat sequence motif (X-[STAV]-X-[LIV]-[GAED]-X) and adopt a left-handed parallel beta helix (LbH) structure. The active enzyme is a trimer with CoA and substrate binding sites at the interface of two separate LbH subunits. XATs are implicated in inactivating xenobiotics leading to xenobiotic resistance in patients.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489550389  46 YLMPDRDDV--DKLVIGSFCSIGSGAAFIMAGNqgHRAEWASTFPFHFMHEEPAFAGAVNGYQPAGDTLIGHDVWIGTEA 123
Cdd:cd03349    9 YGSGPDCDVggDKLSIGKFCSIAPGVKIGLGGN--HPTDWVSTYPFYIFGGEWEDDAKFDDWPSKGDVIIGNDVWIGHGA 86

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 489550389 124 MFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRKRFSDGDIQNLLEMAWWDWP 182
Cdd:cd03349   87 TILPGVTIGDGAVIAAGAVVTKDVPPYAIVGGNPAKVIRYRFDEETIERLLALKWWDWP 145

phosphonate metabolism protein, transferase hexapeptide repeat family; This family of proteins contains copies of the Bacterial transferase hexapeptide repeat family (pfam00132) and is only found in operons encoding the phosphonate C-P lyase system (GenProp0232). Many C-P lyase operons, however, lack a homolog of this protein.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489550389   40 FDDCArYLMpDRDDVDKLVIGSFCSIGSGAAfIMAGNqgHRAEWASTFpfHFMHEEPAFA------GAVNGYQPAGDTLI 113
Cdd:TIGR03308  39 LGDYS-YVM-RDCDIIYTTIGKFCSIAAMVR-INATN--HPMERPTLH--HFTYRAAMYFddasddADFFAWRRAKRVTI 111

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 489550389  114 GHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRKRFSDGDIQNLLEMAWWDWPLADIEAAMP 191
Cdd:TIGR03308 112 GHDVWIGHGAVILPGVTIGNGAVIAAGAVVTKDVAPYTIVAGVPAKLIRRRFPPEIAARIEALAWWDWDHETLREALP 189

Bacterial transferase hexapeptide (six repeats);

                          10        20        30
                  ....*....|....*....|....*....|
gi 489550389  110 DTLIGHDVWIGTEAMFMPGVRVGHGAIIGS 139
Cdd:pfam00132   1 GTVIGDNVLIGPNAVIGGGVIIGDNVIIGA 30

Xenobiotic acyltransferase (XAT): The XAT class of hexapeptide acyltransferases is composed of a large number of microbial enzymes that catalyze the CoA-dependent acetylation of a variety of hydroxyl-bearing acceptors such as chloramphenicol and streptogramin, among others. Members of this class of enzymes include Enterococcus faecium streptogramin A acetyltransferase and Pseudomonas aeruginosa chloramphenicol acetyltransferase. They contain repeated copies of a six-residue hexapeptide repeat sequence motif (X-[STAV]-X-[LIV]-[GAED]-X) and adopt a left-handed parallel beta helix (LbH) structure. The active enzyme is a trimer with CoA and substrate binding sites at the interface of two separate LbH subunits. XATs are implicated in inactivating xenobiotics leading to xenobiotic resistance in patients.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489550389  46 YLMPDRDDV--DKLVIGSFCSIGSGAAFIMAGNqgHRAEWASTFPFHFMHEEPAFAGAVNGYQPAGDTLIGHDVWIGTEA 123
Cdd:cd03349    9 YGSGPDCDVggDKLSIGKFCSIAPGVKIGLGGN--HPTDWVSTYPFYIFGGEWEDDAKFDDWPSKGDVIIGNDVWIGHGA 86

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 489550389 124 MFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRKRFSDGDIQNLLEMAWWDWP 182
Cdd:cd03349   87 TILPGVTIGDGAVIAAGAVVTKDVPPYAIVGGNPAKVIRYRFDEETIERLLALKWWDWP 145

phosphonate metabolism protein, transferase hexapeptide repeat family; This family of proteins contains copies of the Bacterial transferase hexapeptide repeat family (pfam00132) and is only found in operons encoding the phosphonate C-P lyase system (GenProp0232). Many C-P lyase operons, however, lack a homolog of this protein.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489550389   40 FDDCArYLMpDRDDVDKLVIGSFCSIGSGAAfIMAGNqgHRAEWASTFpfHFMHEEPAFA------GAVNGYQPAGDTLI 113
Cdd:TIGR03308  39 LGDYS-YVM-RDCDIIYTTIGKFCSIAAMVR-INATN--HPMERPTLH--HFTYRAAMYFddasddADFFAWRRAKRVTI 111

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 489550389  114 GHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRKRFSDGDIQNLLEMAWWDWPLADIEAAMP 191
Cdd:TIGR03308 112 GHDVWIGHGAVILPGVTIGNGAVIAAGAVVTKDVAPYTIVAGVPAKLIRRRFPPEIAARIEALAWWDWDHETLREALP 189

wcaF-like: This group is composed of the protein product of the E. coli wcaF gene and similar proteins. WcaF is part of the gene cluster responsible for the biosynthesis of the extracellular polysaccharide colanic acid. The wcaF protein is predicted to contain a left-handed parallel beta-helix (LbH) domain encoded by imperfect tandem repeats of a hexapeptide repeat motif (X-[STAV]-X-[LIV]-[GAED]-X). Proteins containing hexapeptide repeats are often enzymes showing acyltransferase activity. Many are trimeric in their active forms.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 489550389  52 DDVDKLVIGSFCSIgSGAAFIMAGNQGHRAewaSTFPFHfmheepafagavngyqpAGDTLIGHDVWIGTEAMFMPGVRV 131
Cdd:cd05825   19 YNLAPVTIGSDACI-SQGAYLCTGSHDYRS---PAFPLI-----------------TAPIVIGDGAWVAAEAFVGPGVTI 77

                         90       100       110
                 ....*....|....*....|....*....|
gi 489550389 132 GHGAIIGSRALVTGDVEPYAIVGGNPARTI 161
Cdd:cd05825   78 GEGAVVGARSVVVRDLPAWTVYAGNPAVPV 107

Maltose O-acetyltransferase (MAT) and Galactoside O-acetyltransferase (GAT): MAT and GAT catalyze the CoA-dependent acetylation of the 6-hydroxyl group of their respective sugar substrates. MAT acetylates maltose and glucose exclusively at the C6 position of the nonreducing end glucosyl moiety. GAT specifically acetylates galactopyranosides. Furthermore, MAT shows higher affinity toward artificial substrates containing an alkyl or hydrophobic chain as well as a glucosyl unit. Active MAT and GAT are homotrimers, with each subunit consisting of an N-terminal alpha-helical region and a C-terminal left-handed parallel alpha-helix (LbH) subdomain with 6 turns, each containing three imperfect tandem repeats of a hexapeptide repeat motif (X-[STAV]-X-[LIV]-[GAED]-X).

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 489550389 113 IGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTI 161
Cdd:cd03357  121 IGDNVWIGGGVIILPGVTIGDNSVIGAGSVVTKDIPANVVAAGNPARVI 169

putative acyl transferase; Provisional

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 489550389 113 IGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRKRF 165
Cdd:PRK10502 127 IGEGCWLAADVFVAPGVTIGSGAVVGARSSVFKSLPANTICRGNPAVPIRPRV 179

sugar O-acyltransferase, sialic acid O-acetyltransferase NeuD family; This family of proteins includes the characterized NeuD sialic acid O-acetyltransferase enzymes from E. coli and Streptococcus agalactiae (group B strep). These two are quite closely related to one another, so extension of this annotation to other members of the family in unsupported without additional independent evidence. The neuD gene is often observed in close proximity to the neuABC genes for the biosynthesis of CMP-N-acetylneuraminic acid (CMP-sialic acid), and NeuD sequences from these organisms were used to construct the seed for this model. Nevertheless, there are numerous instances of sequences identified by this model which are observed in a different genomic context (although almost universally in exopolysaccharide biosynthesis-related loci), as well as in genomes for which the biosynthesis of sialic acid (SA) is undemonstrated. Even in the cases where the association with SA biosynthesis is strong, it is unclear in the literature whether the biological substrate is SA iteself, CMP-SA, or a polymer containing SA. Similarly, it is unclear to what extent the enzyme has a preference for acetylation at the 7, 8 or 9 positions. In the absence of evidence of association with SA, members of this family may be involved with the acetylation of differring sugar substrates, or possibly the delivery of alternative acyl groups. The closest related sequences to this family (and those used to root the phylogenetic tree constructed to create this model) are believed to be succinyltransferases involved in lysine biosynthesis. These proteins contain repeats of the bacterial transferase hexapeptide (pfam00132), although often these do not register above the trusted cutoff.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 489550389  108 AGDTLIGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPA 158
Cdd:TIGR03570 151 SGGVVIGEGVFIGAGATIIQGVTIGAGAIVGAGAVVTKDIPDGGVVVGVPA 201

galactoside O-acetyltransferase; Reviewed

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 489550389 113 IGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRK 163
Cdd:PRK09527 134 IGNNVWIGSHVVINPGVTIGDNSVIGAGSVVTKDIPPNVVAAGVPCRVIRE 184

UDP-3-O-acyl-glucosamine N-acyltransferase (LpxD): The enzyme catalyzes the transfer of 3-hydroxymyristic acid or 3-hydroxy-arachidic acid, depending on the organism, from the acyl carrier protein (ACP) to UDP-3-O-acyl-glucosamine to produce UDP-2,3-diacyl-GlcNAc. This constitutes the third step in the lipid A biosynthetic pathway in Gram-negative bacteria. LpxD is a homotrimer, with each subunit consisting of a novel combination of an N-terminal uridine-binding domain, a core lipid-binding left-handed parallel beta helix (LbH) domain, and a C-terminal alpha-helical extension. The LbH domain contains 9 turns, each containing three imperfect tandem repeats of a hexapeptide repeat motif (X-[STAV]-X-[LIV]-[GAED]-X).

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 489550389 108 AGDTLIGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRK 163
Cdd:cd03352  148 AGSTTIGDNVIIGGQVGIAGHLTIGDGVVIGAGSGVTSIVPPGEYVSGTPAQPHRE 203

Gamma carbonic anhydrase-like: This family is composed of gamma carbonic anhydrase (CA), Ferripyochelin Binding Protein (FBP), E. coli paaY protein, and similar proteins. CAs are zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide in a two-step mechanism, involving the nucleophilic attack of a zinc-bound hydroxide ion on carbon dioxide, followed by the regeneration of the active site by ionization of the zinc-bound water molecule and removal of a proton from the active site. They are ubiquitous enzymes involved in fundamental processes like photosynthesis, respiration, pH homeostasis and ion transport. There are three evolutionary distinct groups - alpha, beta and gamma carbonic anhydrases - which show no significant sequence identity or structural similarity. Gamma CAs are trimeric enzymes with left-handed parallel beta helix (LbH) structural domain.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 489550389 113 IGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGD--VEPYAIVGGNPARTIRKrFSDGDIQNLLEMA 177
Cdd:cd04645   80 IGDNCLIGMGAIILDGAVIGKGSIVAAGSLVPPGkvIPPGSLVAGSPAKVVRE-LTDEEIAELRESA 145

Serine acetyltransferase (SAT): SAT catalyzes the CoA-dependent acetylation of the side chain hydroxyl group of L-serine to form O-acetylserine, as the first step of a two-step biosynthetic pathway in bacteria and plants leading to the formation of L-cysteine. This reaction represents a key metabolic point of regulation for the cysteine biosynthetic pathway due to its feedback inhibition by cysteine. The enzyme is a 175 kDa homohexamer, composed of a dimer of homotrimers. Each subunit contains an N-terminal alpha helical region and a C-terminal left-handed beta-helix (LbH) subdomain with 5 turns, each containing a hexapeptide repeat motif characteristic of the acyltransferase superfamily of enzymes. The trimer interface mainly involves the C-terminal LbH subdomain while the dimer (of trimers) interface is mediated by the N-terminal alpha helical subdomain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 489550389 113 IGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNP 157
Cdd:cd03354   57 IGDNVVIGAGAKILGNITIGDNVKIGANAVVTKDVPANSTVVGVP 101

Bacterial transferase hexapeptide (six repeats);

                          10        20        30
                  ....*....|....*....|....*....|
gi 489550389  110 DTLIGHDVWIGTEAMFMPGVRVGHGAIIGS 139
Cdd:pfam00132   1 GTVIGDNVLIGPNAVIGGGVIIGDNVIIGA 30

UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferase [Cell wall/membrane/envelope biogenesis]; UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferase is part of the Pathway/BioSystem: Lipid A biosynthesis

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 489550389 108 AGDTLIGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRK 163
Cdd:COG1044  256 AGSTKIGDNVVIGGQVGIAGHLTIGDGVIIGAQSGVTKSIPEGGVYSGSPAQPHRE 311

serine acetyltransferase

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 489550389 113 IGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIR 162
Cdd:PLN02739 260 IGDGALLGACVTILGNISIGAGAMVAAGSLVLKDVPSHSMVAGNPAKLIG 309

serine acetyltransferase

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 489550389 113 IGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTI 161
Cdd:PLN02357 281 IGDGVLIGAGTCILGNITIGEGAKIGAGSVVLKDVPPRTTAVGNPARLI 329

bifunctional UDP-N-acetylglucosamine diphosphorylase/glucosamine-1-phosphate N-acetyltransferase GlmU;

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 489550389 111 TLIGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIR 162
Cdd:PRK14353 381 TEIGAGAFIGSNSALVAPVTIGDGAYIASGSVITEDVPDDALALGRARQETK 432

serine acetyltransferase; Provisional

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 489550389 117 VWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPYAIVGGNPARTIRKRFSD 167
Cdd:PRK11132 200 VMIGAGAKILGNIEVGRGAKIGAGSVVLQPVPPHTTAAGVPARIVGKPESD 250

UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferase; Provisional

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 489550389 108 AGDTLIGHDVWIGTEAMFMPGVRVGHGAIIGSRALVTGDVEPY-AIVGGNPARTIR 162
Cdd:PRK00892 259 AGSTKIGRYCMIGGQVGIAGHLEIGDGVTITAMSGVTKSIPEPgEYSSGIPAQPNK 314