THGA_ECOLI
ID THGA_ECOLI Reviewed; 203 AA.
AC P07464; P77862; Q2MC82;
DT 01-APR-1988, integrated into UniProtKB/Swiss-Prot.
DT 01-APR-1988, sequence version 1.
DT 03-AUG-2022, entry version 169.
DE RecName: Full=Galactoside O-acetyltransferase {ECO:0000303|PubMed:7592843};
DE Short=GAT;
DE EC=2.3.1.18 {ECO:0000269|PubMed:14009486, ECO:0000269|PubMed:4630409};
DE AltName: Full=Acetyl-CoA:galactoside 6-O-acetyltransferase {ECO:0000303|PubMed:4630409};
DE AltName: Full=Thiogalactoside acetyltransferase;
DE AltName: Full=Thiogalactoside transacetylase {ECO:0000303|PubMed:14009486};
GN Name=lacA; OrderedLocusNames=b0342, JW0333;
OS Escherichia coli (strain K12).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=83333;
RN [1]
RP PROTEIN SEQUENCE.
RX PubMed=3922433; DOI=10.1016/s0300-9084(85)80235-2;
RA Fowler A.V., Hediger M.A., Musso R.E., Zabin I.;
RT "The amino acid sequence of thiogalactoside transacetylase of Escherichia
RT coli.";
RL Biochimie 67:101-108(1985).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=3901000; DOI=10.1073/pnas.82.19.6414;
RA Hediger M.A., Johnson D.F., Nierlich D.P., Zabin I.;
RT "DNA sequence of the lactose operon: the lacA gene and the transcriptional
RT termination region.";
RL Proc. Natl. Acad. Sci. U.S.A. 82:6414-6418(1985).
RN [3]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=K12 / MG1655 / ATCC 47076;
RA Chung E., Allen E., Araujo R., Aparicio A.M., Davis K., Duncan M.,
RA Federspiel N., Hyman R., Kalman S., Komp C., Kurdi O., Lew H., Lin D.,
RA Namath A., Oefner P., Roberts D., Schramm S., Davis R.W.;
RT "Sequence of minutes 4-25 of Escherichia coli.";
RL Submitted (JAN-1997) to the EMBL/GenBank/DDBJ databases.
RN [4]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=K12 / MG1655 / ATCC 47076;
RX PubMed=9278503; DOI=10.1126/science.277.5331.1453;
RA Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V.,
RA Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F.,
RA Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B.,
RA Shao Y.;
RT "The complete genome sequence of Escherichia coli K-12.";
RL Science 277:1453-1462(1997).
RN [5]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX PubMed=16738553; DOI=10.1038/msb4100049;
RA Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S.,
RA Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.;
RT "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655
RT and W3110.";
RL Mol. Syst. Biol. 2:E1-E5(2006).
RN [6]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-26.
RX PubMed=6444453; DOI=10.1038/283541a0;
RA Buechel D.E., Gronenborn B., Mueller-Hill B.;
RT "Sequence of the lactose permease gene.";
RL Nature 283:541-545(1980).
RN [7]
RP CATALYTIC ACTIVITY.
RX PubMed=14009486;
RA Zabin I., Kepes A., Monod J.;
RT "Thiogalactoside transacetylase.";
RL J. Biol. Chem. 237:253-257(1962).
RN [8]
RP FUNCTION, CATALYTIC ACTIVITY, AND BIOPHYSICOCHEMICAL PROPERTIES.
RX PubMed=4630409; DOI=10.1021/bi00727a031;
RA Musso R.E., Zabin I.;
RT "Substrate specificity and kinetic studies on thiogalactoside
RT transacetylase.";
RL Biochemistry 12:553-557(1973).
RN [9]
RP FUNCTION, SUBUNIT, AND MUTAGENESIS OF HIS-115.
RX PubMed=7592843; DOI=10.1074/jbc.270.44.26326;
RA Lewendon A., Ellis J., Shaw W.V.;
RT "Structural and mechanistic studies of galactoside acetyltransferase, the
RT Escherichia coli LacA gene product.";
RL J. Biol. Chem. 270:26326-26331(1995).
RN [10]
RP X-RAY CRYSTALLOGRAPHY (3.2 ANGSTROMS) IN COMPLEX WITH COENZYME A AND
RP SUBSTRATE ANALOG, AND SUBUNIT.
RX PubMed=11937062; DOI=10.1016/s0969-2126(02)00741-4;
RA Wang X.G., Olsen L.R., Roderick S.L.;
RT "Structure of the lac operon galactoside acetyltransferase.";
RL Structure 10:581-588(2002).
CC -!- FUNCTION: Catalyzes the CoA-dependent transfer of an acetyl group to
CC the 6-O-methyl position of a range of galactosides, glucosides, and
CC lactosides (PubMed:14009486, PubMed:4630409, PubMed:7592843). May
CC assist cellular detoxification by acetylating non-metabolizable
CC pyranosides, thereby preventing their reentry into the cell (Probable).
CC {ECO:0000269|PubMed:14009486, ECO:0000269|PubMed:4630409,
CC ECO:0000269|PubMed:7592843, ECO:0000305|PubMed:11937062}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a beta-D-galactoside + acetyl-CoA = a 6-acetyl-beta-D-
CC galactoside + CoA; Xref=Rhea:RHEA:15713, ChEBI:CHEBI:28034,
CC ChEBI:CHEBI:28250, ChEBI:CHEBI:57287, ChEBI:CHEBI:57288; EC=2.3.1.18;
CC Evidence={ECO:0000269|PubMed:14009486, ECO:0000269|PubMed:4630409};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=0.18 mM for acetyl-CoA {ECO:0000269|PubMed:4630409};
CC KM=0.104 mM for acetyl-CoA {ECO:0000269|PubMed:7592843};
CC KM=0.77 M for isopropyl beta-D-1-thiogalactopyranoside
CC {ECO:0000269|PubMed:4630409};
CC KM=63.4 mM for p-nitrophenyl-b-D-galactopyranoside
CC {ECO:0000269|PubMed:7592843};
CC -!- SUBUNIT: Homotrimer. {ECO:0000269|PubMed:11937062,
CC ECO:0000269|PubMed:7592843}.
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:3922433}.
CC -!- PTM: The N-terminus of this protein is heterogeneous because the
CC initiator methionine is only partially cleaved.
CC {ECO:0000269|PubMed:3922433}.
CC -!- SIMILARITY: Belongs to the transferase hexapeptide repeat family.
CC {ECO:0000305}.
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DR EMBL; J01636; AAA24055.1; -; Genomic_DNA.
DR EMBL; X51872; CAA36162.1; -; Genomic_DNA.
DR EMBL; U73857; AAB18066.1; -; Genomic_DNA.
DR EMBL; U00096; AAC73445.1; -; Genomic_DNA.
DR EMBL; AP009048; BAE76124.1; -; Genomic_DNA.
DR EMBL; V00295; CAA23572.1; -; Genomic_DNA.
DR PIR; A94061; XXECTG.
DR RefSeq; NP_414876.1; NC_000913.3.
DR RefSeq; WP_001335915.1; NZ_SSZK01000061.1.
DR PDB; 1KQA; X-ray; 3.20 A; A/B/C=1-203.
DR PDB; 1KRR; X-ray; 2.50 A; A/B/C=1-203.
DR PDB; 1KRU; X-ray; 2.80 A; A/B/C=1-203.
DR PDB; 1KRV; X-ray; 2.80 A; A/B/C=1-203.
DR PDBsum; 1KQA; -.
DR PDBsum; 1KRR; -.
DR PDBsum; 1KRU; -.
DR PDBsum; 1KRV; -.
DR AlphaFoldDB; P07464; -.
DR SMR; P07464; -.
DR BioGRID; 4263184; 12.
DR DIP; DIP-10078N; -.
DR IntAct; P07464; 4.
DR STRING; 511145.b0342; -.
DR DrugBank; DB02632; 4-nitrophenyl-beta-D-galactoside.
DR DrugBank; DB01992; Coenzyme A.
DR DrugBank; DB01862; Isopropyl beta-D-thiogalactopyranoside.
DR PaxDb; P07464; -.
DR PRIDE; P07464; -.
DR EnsemblBacteria; AAC73445; AAC73445; b0342.
DR EnsemblBacteria; BAE76124; BAE76124; BAE76124.
DR GeneID; 945674; -.
DR KEGG; ecj:JW0333; -.
DR KEGG; eco:b0342; -.
DR PATRIC; fig|511145.12.peg.350; -.
DR EchoBASE; EB0519; -.
DR eggNOG; COG0110; Bacteria.
DR HOGENOM; CLU_051638_3_0_6; -.
DR InParanoid; P07464; -.
DR OMA; RIKFVEF; -.
DR PhylomeDB; P07464; -.
DR BioCyc; EcoCyc:GALACTOACETYLTRAN-MON; -.
DR BioCyc; MetaCyc:GALACTOACETYLTRAN-MON; -.
DR BRENDA; 2.3.1.18; 2026.
DR EvolutionaryTrace; P07464; -.
DR PRO; PR:P07464; -.
DR Proteomes; UP000000318; Chromosome.
DR Proteomes; UP000000625; Chromosome.
DR GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0008870; F:galactoside O-acetyltransferase activity; IDA:EcoCyc.
DR GO; GO:0005989; P:lactose biosynthetic process; IEA:UniProtKB-KW.
DR InterPro; IPR001451; Hexapep.
DR InterPro; IPR018357; Hexapep_transf_CS.
DR InterPro; IPR039369; LacA-like.
DR InterPro; IPR024688; Mac_dom.
DR InterPro; IPR011004; Trimer_LpxA-like_sf.
DR PANTHER; PTHR43017; PTHR43017; 1.
DR Pfam; PF00132; Hexapep; 1.
DR Pfam; PF12464; Mac; 1.
DR SMART; SM01266; Mac; 1.
DR SUPFAM; SSF51161; SSF51161; 1.
DR PROSITE; PS00101; HEXAPEP_TRANSFERASES; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Acyltransferase; Cytoplasm; Direct protein sequencing;
KW Lactose biosynthesis; Reference proteome; Repeat; Transferase.
FT INIT_MET 1
FT /note="Removed; Partial"
FT /evidence="ECO:0000269|PubMed:3922433"
FT CHAIN 2..203
FT /note="Galactoside O-acetyltransferase"
FT /id="PRO_0000068696"
FT ACT_SITE 115
FT /note="Proton donor/acceptor"
FT /evidence="ECO:0000305|PubMed:11937062"
FT BINDING 17
FT /ligand="substrate"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRV"
FT BINDING 71
FT /ligand="substrate"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRV"
FT BINDING 85
FT /ligand="acetyl-CoA"
FT /ligand_id="ChEBI:CHEBI:57288"
FT /ligand_note="ligand shared between dimeric partners"
FT /note="in other chain"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRR"
FT BINDING 85
FT /ligand="substrate"
FT /ligand_note="ligand shared between dimeric partners"
FT /note="in other chain"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRV"
FT BINDING 93
FT /ligand="substrate"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRV"
FT BINDING 142
FT /ligand="acetyl-CoA"
FT /ligand_id="ChEBI:CHEBI:57288"
FT /ligand_note="ligand shared between dimeric partners"
FT /note="in other chain"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRR"
FT BINDING 160
FT /ligand="acetyl-CoA"
FT /ligand_id="ChEBI:CHEBI:57288"
FT /ligand_note="ligand shared between dimeric partners"
FT /note="in other chain"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRR"
FT BINDING 165..166
FT /ligand="acetyl-CoA"
FT /ligand_id="ChEBI:CHEBI:57288"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRV"
FT BINDING 180
FT /ligand="acetyl-CoA"
FT /ligand_id="ChEBI:CHEBI:57288"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRV"
FT BINDING 183
FT /ligand="acetyl-CoA"
FT /ligand_id="ChEBI:CHEBI:57288"
FT /ligand_note="ligand shared between dimeric partners"
FT /note="in other chain"
FT /evidence="ECO:0000269|PubMed:11937062,
FT ECO:0007744|PDB:1KRR"
FT SITE 85
FT /note="Transition state stabilizer"
FT /evidence="ECO:0000305|PubMed:11937062"
FT MUTAGEN 115
FT /note="H->A: Results in an 1800-fold decrease in catalytic
FT activity."
FT /evidence="ECO:0000269|PubMed:7592843"
FT HELIX 5..11
FT /evidence="ECO:0007829|PDB:1KRR"
FT HELIX 22..37
FT /evidence="ECO:0007829|PDB:1KRR"
FT HELIX 44..54
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 55..57
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 68..71
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 76..78
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 88..91
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 96..98
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 109..114
FT /evidence="ECO:0007829|PDB:1KRR"
FT TURN 119..121
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 127..129
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 132..134
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 172..175
FT /evidence="ECO:0007829|PDB:1KRR"
FT TURN 176..179
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 180..184
FT /evidence="ECO:0007829|PDB:1KRR"
FT HELIX 187..189
FT /evidence="ECO:0007829|PDB:1KRR"
FT STRAND 192..194
FT /evidence="ECO:0007829|PDB:1KRU"
SQ SEQUENCE 203 AA; 22799 MW; 31C7FEA0B0150D70 CRC64;
MNMPMTERIR AGKLFTDMCE GLPEKRLRGK TLMYEFNHSH PSEVEKRESL IKEMFATVGE
NAWVEPPVYF SYGSNIHIGR NFYANFNLTI VDDYTVTIGD NVLIAPNVTL SVTGHPVHHE
LRKNGEMYSF PITIGNNVWI GSHVVINPGV TIGDNSVIGA GSIVTKDIPP NVVAAGVPCR
VIREINDRDK HYYFKDYKVE SSV
