2p53
From Proteopedia
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Crystal structure of N-acetyl-D-glucosamine-6-phosphate deacetylase D273N mutant complexed with N-acetyl phosphonamidate-d-glucosamine-6-phosphate
Overview
NagA catalyzes the hydrolysis of N-acetyl-d-glucosamine-6-phosphate to, d-glucosamine-6-phosphate and acetate. X-ray crystal structures of NagA, from Escherichia coli were determined to establish the number and ligation, scheme for the binding of zinc to the active site and to elucidate the, molecular interactions between the protein and substrate. The, three-dimensional structures of the apo-NagA, Zn-NagA, and the D273N, mutant enzyme in the presence of a tight-binding, N-methylhydroxyphosphinyl-d-glucosamine-6-phosphate inhibitor were, determined. The structure of the Zn-NagA confirms that this enzyme binds a, single divalent cation at the beta-position in the active site via, ligation to Glu-131, His-195, and His-216. A water molecule completes the, ligation shell, which is also in position to be hydrogen bonded to, Asp-273. In the structure of NagA bound to the tight binding inhibitor, that mimics the tetrahedral intermediate, the methyl phosphonate moiety, has displaced the hydrolytic water molecule and is directly coordinated to, the zinc within the active site. The side chain of Asp-273 is positioned, to activate the hydrolytic water molecule via general base catalysis and, to deliver this proton to the amino group upon cleavage of the amide bond, of the substrate. His-143 is positioned to help polarize the carbonyl, group of the substrate in conjunction with Lewis acid catalysis by the, bound zinc. The inhibitor is bound in the alpha-configuration at the, anomeric carbon through a hydrogen bonding interaction of the hydroxyl, group at C-1 with the side chain of His-251. The phosphate group of the, inhibitor attached to the hydroxyl at C-6 is ion paired with Arg-227 from, the adjacent subunit. NagA from Thermotoga maritima was shown to require a, single divalent cation for full catalytic activity.
About this Structure
2P53 is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as N-acetylglucosamine-6-phosphate deacetylase, with EC number 3.5.1.25 Full crystallographic information is available from OCA.
Reference
Structural diversity within the mononuclear and binuclear active sites of N-acetyl-D-glucosamine-6-phosphate deacetylase., Hall RS, Brown S, Fedorov AA, Fedorov EV, Xu C, Babbitt PC, Almo SC, Raushel FM, Biochemistry. 2007 Jul 10;46(27):7953-62. Epub 2007 Jun 13. PMID:17567048
Page seeded by OCA on Wed Jan 23 14:26:00 2008
