1gwj

From Proteopedia

Revision as of 14:16, 5 November 2007

MORPHINONE REDUCTASE

Overview

The crystal structure of the NADH-dependent bacterial flavoenzyme, morphinone reductase (MR) has been determined at 2.2-A resolution in, complex with the oxidizing substrate codeinone. The structure reveals a, dimeric enzyme comprising two 8-fold beta/alpha barrel domains, each bound, to FMN, and a subunit folding topology and mode of flavin-binding similar, to that found in Old Yellow Enzyme (OYE) and pentaerythritol tetranitrate, (PETN) reductase. The subunit interface of MR is formed by interactions, from an N-terminal beta strand and helices 2 and 8 of the barrel domain, and is different to that seen in OYE. The active site structures of MR, OYE, and PETN reductase are highly conserved reflecting the ability of, these enzymes to catalyze "generic" reactions such as the reduction of, 2-cyclohexenone. A region of polypeptide presumed to define the reducing, coenzyme specificity is identified by comparison of the MR structure, (NADH-dependent) with that of PETN reductase (NADPH-dependent). The active, site acid identified in OYE (Tyr-196) and conserved in PETN reductase, (Tyr-186) is replaced by Cys-191 in MR. Mutagenesis studies have, established that Cys-191 does not act as a crucial acid in the mechanism, of reduction of the olefinic bond found in 2-cyclohexenone and codeinone.

About this Structure

1GWJ is a Single protein structure of sequence from Pseudomonas putida with FMN as ligand. Structure known Active Site: FMN. Full crystallographic information is available from OCA.

Reference

Crystal structure of bacterial morphinone reductase and properties of the C191A mutant enzyme., Barna T, Messiha HL, Petosa C, Bruce NC, Scrutton NS, Moody PC, J Biol Chem. 2002 Aug 23;277(34):30976-83. Epub 2002 Jun 4. PMID:12048188

Page seeded by OCA on Mon Nov 5 16:21:24 2007