1KQA

GALACTOSIDE ACETYLTRANSFERASE IN COMPLEX WITH COENZYME A

Summary for 1KQA

• Entry DOI: 10.2210/pdb1kqa/pdb
• Related: 1KRR 1KRU 1KRV
• Descriptor: GALACTOSIDE O-ACETYLTRANSFERASE, COENZYME A (2 entities in total)
• Functional Keywords: left-handed parallel beta helix, transferase
• Biological source: Escherichia coli
• Cellular location: Cytoplasm: P07464
• Total number of polymer chains: 3
• Total formula weight: 70783.60

Authors

Wang, X.-G.,Olsen, L.R.,Roderick, S.L. (deposition date: 2002-01-04, release date: 2002-04-10, Last modification date: 2024-02-14)

Primary citation

Wang, X.G.,Olsen, L.R.,Roderick, S.L.
Structure of the lac operon galactoside acetyltransferase.
Structure, 10:581-588, 2002

PubMed Abstract: The galactoside acetyltransferase (thiogalactoside transacetylase) of Escherichia coli (GAT, LacA, EC 2.3.1.18) is a gene product of the classical lac operon. GAT may assist cellular detoxification by acetylating nonmetabolizable pyranosides, thereby preventing their reentry into the cell. The structure of GAT has been solved in binary complexes with acetyl-CoA or CoA and in ternary complexes with CoA and the nonphysiological acceptor substrates isopropyl beta-D-thiogalactoside (IPTG) or p-nitrophenyl beta-D-galactopyranoside (PNPbetaGal). A hydrophobic cleft that binds the thioisopropyl and p-nitrophenyl aglycones of IPTG and PNPbetaGal may discriminate against substrates with hydrophilic substituents at this position, such as lactose, or inducers of the lac operon. An extended loop projecting from the left-handed parallel beta helix domain contributes His115, which is in position to facilitate attack of the C6-hydroxyl group of the substrate on the thioester.

PubMed: 11937062
DOI: 10.1016/S0969-2126(02)00741-4

Experimental method

X-RAY DIFFRACTION (3.2 Å)