1oaf: Difference between revisions
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==Overview== | ==Overview== | ||
Heme peroxidases catalyze the H2O2-dependent oxidation of a variety of | 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== | ==About this Structure== | ||
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[[Category: L-ascorbate peroxidase]] | [[Category: L-ascorbate peroxidase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Moody, P | [[Category: Moody, P C.E.]] | ||
[[Category: Raven, E | [[Category: Raven, E L.]] | ||
[[Category: Sharp, K | [[Category: Sharp, K H.]] | ||
[[Category: ASC]] | [[Category: ASC]] | ||
[[Category: HEM]] | [[Category: HEM]] | ||
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[[Category: peroxide scavenge]] | [[Category: peroxide scavenge]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:15:18 2008'' | ||
Revision as of 15:15, 21 February 2008
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ASCOBATE PEROXIDASE FROM SOYBEAN CYTOSOL IN COMPLEX WITH ASCORBATE
OverviewOverview
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 StructureAbout this Structure
1OAF is a Single protein structure of sequence from Glycine max with , and as ligands. Active as L-ascorbate peroxidase, with EC number 1.11.1.11 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
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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