1OAF

Ascobate peroxidase from soybean cytosol in complex with ascorbate

Summary for 1OAF

• Entry DOI: 10.2210/pdb1oaf/pdb
• Related: 1OAG
• Descriptor: ASCORBATE PEROXIDASE, PROTOPORPHYRIN IX CONTAINING FE, SODIUM ION, ... (5 entities in total)
• Functional Keywords: oxidoreductase, heme peroxidase, peroxide scavenge, ascorbate peroxidase
• Biological source: GLYCINE MAX (SOYBEAN)
• Total number of polymer chains: 1
• Total formula weight: 29177.51

Authors

Sharp, K.H.,Raven, E.L.,Moody, P.C.E. (deposition date: 2003-01-13, release date: 2003-03-20, Last modification date: 2023-12-13)

Primary citation

Sharp, K.H.,Mewies, M.,Moody, P.C.E.,Raven, E.L.
Crystal Structure of the Ascorbate Peroxidase-Ascorbate Complex
Nat.Struct.Biol., 10:303-, 2003

PubMed Abstract: 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.

PubMed: 12640445
DOI: 10.1038/NSB913

Experimental method

X-RAY DIFFRACTION (1.4 Å)