1evi

From Proteopedia

Revision as of 12:14, 20 November 2007

THREE-DIMENSIONAL STRUCTURE OF THE PURPLE INTERMEDIATE OF PORCINE KIDNEY D-AMINO ACID OXIDASE

Overview

The three-dimensional structure of the purple intermediate of porcine, kidney D-amino acid oxidase (DAO) was solved by cryo-X-ray, crystallography; the purple intermediate is known to comprise a complex, between the dehydrogenated product, an imino acid, and the reduced form of, DAO. The crystalline purple intermediate was obtained by anaerobically, soaking crystals of oxidized DAO in a buffer containing excess D-proline, as the substrate. The dehydrogenated product, delta(1)-pyrrolidine-2-carboxylate (DPC), is found sandwiched between the, phenol ring of Tyr 224 and the planar reduced flavin ring. The cationic, protonated imino nitrogen is within hydrogen-bonding distance of the, backbone carbonyl oxygen of Gly 313. The carboxyl group of DPC is, recognized by the Arg 283 guanidino and Tyr 228 hydroxyl groups through, ion-pairing and hydrogen-bonding, respectively. The (+)HN=C double bond of, DPC overlaps the N(5)-C(4a) bond of reduced flavin. The electrostatic, effect of the cationic nitrogen of DPC is suggested to shift the resonance, hybridization of anionic reduced flavin toward a canonical form with a, negative charge at C(4a), thereby augmenting the electron density at, C(4a), from which electrons are transferred to molecular oxygen during, reoxidation of reduced flavin. The reactivity of reduced flavin in the, purple intermediate, therefore, is enhanced through the alignment of DPC, with respect to reduced flavin.

About this Structure

1EVI is a Single protein structure of sequence from Sus scrofa with FAD and 2PC as ligands. Active as D-amino-acid oxidase, with EC number 1.4.3.3 Full crystallographic information is available from OCA.

Reference

Three-dimensional structure of the purple intermediate of porcine kidney D-amino acid oxidase. Optimization of the oxidative half-reaction through alignment of the product with reduced flavin., Mizutani H, Miyahara I, Hirotsu K, Nishina Y, Shiga K, Setoyama C, Miura R, J Biochem (Tokyo). 2000 Jul;128(1):73-81. PMID:10876160

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