1oaf: Difference between revisions

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.

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].  

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