1td9
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Crystal Structure of a Phosphotransacetylase from Bacillus subtilis
OverviewOverview
Phosphotransacetylase (Pta) [EC 2.3.1.8] plays a major role in acetate, metabolism by catalyzing the reversible transfer of the acetyl group, between coenzyme A (CoA) and orthophosphate:, CH(3)COSCoA+HPO(4)(2-)<-->CH(3)COOPO(3)(2-) +CoASH. In this study, we, report the crystal structures of Pta from Bacillus subtilis at 2.75 A, resolution and its complex with acetyl phosphate, one of its substrates, at 2.85 A resolution. In addition, the Pta activity of the enzyme has been, assayed. The enzyme folds into an alpha/beta architecture with two domains, separated by a prominent cleft, very similar to two other known Pta, structures. The enzyme-acetyl phosphate complex structure reveals a few, potential substrate binding sites. Two of them are located in the middle, of the interdomain cleft: each one is surrounded by a region of strictly, and highly conserved residues. High structural similarities are found with, 4-hydroxythreonine-4-phosphate dehydrogenase (PdxA), and isocitrate and, isopropylmalate dehydrogenases, all of which utilize NADP+ as their, cofactor, which binds in the interdomain cleft. Their substrate binding, sites are close to the acetyl phosphate binding sites of Pta in the cleft, as well. These results suggest that the CoA is likely to bind to the, interdomain cleft of Pta in a similar way as NADP+ binds to the other, three enzymes.
About this StructureAbout this Structure
1TD9 is a Single protein structure of sequence from Bacillus subtilis with SO4 as ligand. Active as Phosphate acetyltransferase, with EC number 2.3.1.8 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of a phosphotransacetylase from Bacillus subtilis and its complex with acetyl phosphate., Xu QS, Jancarik J, Lou Y, Kuznetsova K, Yakunin AF, Yokota H, Adams P, Kim R, Kim SH, J Struct Funct Genomics. 2005 Dec;6(4):269-79. Epub 2005 Nov 9. PMID:16283428
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