1oaf: Difference between revisions
No edit summary |
No edit summary |
||
| Line 5: | Line 5: | ||
==Overview== | ==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 .. | 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== | ||
1OAF is a | 1OAF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Glycine_max Glycine max] with NA, HEM and ASC as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/L-ascorbate_peroxidase L-ascorbate peroxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.11 1.11.1.11] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1OAF OCA]. | ||
==Reference== | ==Reference== | ||
| Line 25: | Line 25: | ||
[[Category: peroxide scavenge]] | [[Category: peroxide scavenge]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:19:05 2007'' | ||
Revision as of 15:13, 5 November 2007
|
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 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.
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
Page seeded by OCA on Mon Nov 5 14:19:05 2007