1oaf

From Proteopedia

Revision as of 14:42, 5 November 2007

ASCOBATE PEROXIDASE FROM SOYBEAN CYTOSOL IN COMPLEX WITH ASCORBATE

Overview

Heme peroxidases catalyze the H2O2-dependent oxidation of a variety of, substrates, most of which are organic. Mechanistically, these enzymes are, well characterized: they share a common catalytic cycle that involves, formation of a two-electron, oxidized Compound I intermediate followed by, two single-electron reduction steps by substrate. The substrate, specificity is more diverse--most peroxidases oxidize small organic, substrates, but there are prominent exceptions--and there is a notable, absence of structural information for a representative, peroxidase-substrate complex. Thus, the features that control substrate, specificity remain undefined. We present the structure of the complex of, ascorbate peroxidase-ascorbate. The structure defines the, ascorbate-binding interaction for the first time and provides new, rationalization of the unusual functional features of the related, cytochrome c peroxidase enzyme, which has been a benchmark for peroxidase, catalysis for more than 20 years. A new mechanism for electron transfer is, proposed that challenges existing views of substrate oxidation in other, peroxidases.

About this Structure

1OAF is a Single protein structure of sequence from Glycine max with NA, HEM and ASC as ligands. Active as L-ascorbate peroxidase, with EC number 1.11.1.11 Structure known Active Site: AC1. Full crystallographic information is available from OCA.

Reference

Crystal structure of the ascorbate peroxidase-ascorbate complex., Sharp KH, Mewies M, Moody PC, Raven EL, Nat Struct Biol. 2003 Apr;10(4):303-7. PMID:12640445

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