Galactoside acetyltransferase

Galactoside acetyltransferase (also known as Galactoside O-acetyltransferase, thiogalactoside transacetylase, β-galactoside transacetylase and GAT) is an enzyme that transfers an acetyl group from acetyl-CoA to β-galactosides, glucosides and lactosides. It is coded for by the lacA gene of the lac operon in E. coli.[1]

GAT in complex with CoA and two molecules/active site of IPTG viewed perpendicular to the molecular threefold axis of the enzyme
Galactoside O-acetyltransferase
Identifiers
EC no.2.3.1.18
CAS no.9029-94-1
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
Search
PMCarticles
PubMedarticles
NCBIproteins
Thiogalactoside acetyltransferase
Identifiers
OrganismEscherichia coli
SymbollacA
Entrez945674
RefSeq (Prot)NP_414876
UniProtP07464
Search for
StructuresSwiss-model
DomainsInterPro

Reaction

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It catalyzes the following reaction:

acetyl-CoA + beta-D-galactosideCoA + 6-acetyl-beta-D-galactoside

The kinetics of the enzyme were delineated in 1995.[2]

Biological role

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The enzyme's role in the classical E.coli lac operon remains unclear.[1][3] However, the enzyme's cellular role may be to detoxify non-metabolizable pyranosides by acetylating them and preventing their reentry into the cell.[1][4]

See also

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References

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  1. ^ a b c Wang XG, Olsen LR, Roderick SL (April 2002). "Structure of the lac operon galactoside acetyltransferase". Structure. 10 (4): 581–8. doi:10.1016/S0969-2126(02)00741-4. PMID 11937062.
  2. ^ Lewendon A, Ellis J, Shaw WV (November 1995). "Structural and mechanistic studies of galactoside acetyltransferase, the Escherichia coli LacA gene product". The Journal of Biological Chemistry. 270 (44): 26326–31. doi:10.1074/jbc.270.44.26326. PMID 7592843.
  3. ^ Roderick SL (June 2005). "The lac operon galactoside acetyltransferase". Comptes Rendus Biologies. 328 (6): 568–75. doi:10.1016/j.crvi.2005.03.005. PMID 15950163.
  4. ^ "Thiogalactoside transacetylase of the lactose operon as an enzyme for detoxification". 1976. {{cite journal}}: Cite journal requires |journal= (help)
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