2nx9

From Proteopedia

Crystal structure of the carboxyltransferase domain of the oxaloacetate decarboxylase Na+ pump from Vibrio cholerae

Overview

Oxaloacetate decarboxylase is a membrane-bound multiprotein complex that, couples oxaloacetate decarboxylation to sodium ion transport across the, membrane. The initial reaction catalyzed by this enzyme machinery is the, carboxyl transfer from oxaloacetate to the prosthetic biotin group. The, crystal structure of the carboxyltransferase at 1.7 A resolution shows a, dimer of alpha(8)beta(8) barrels with an active site metal ion, identified, spectroscopically as Zn(2+), at the bottom of a deep cleft. The enzyme is, completely inactivated by specific mutagenesis of Asp17, His207 and, His209, which serve as ligands for the Zn(2+) metal ion, or by Lys178 near, the active site, suggesting that Zn(2+) as well as Lys178 are essential, for the catalysis. In the present structure this lysine residue is, hydrogen-bonded to Cys148. A potential role of Lys178 as initial acceptor, of the carboxyl group from oxaloacetate is discussed.

About this Structure

2NX9 is a Single protein structure of sequence from Vibrio cholerae with as ligand. Active as Oxaloacetate decarboxylase, with EC number 4.1.1.3 Full crystallographic information is available from OCA.

Reference

Crystal Structure of the Carboxyltransferase Domain of the Oxaloacetate Decarboxylase Na(+) Pump from Vibrio cholerae., Studer R, Dahinden P, Wang WW, Auchli Y, Li XD, Dimroth P, J Mol Biol. 2007 Mar 23;367(2):547-57. Epub 2006 Dec 19. PMID:17270211

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