View source for 1oaf

[[Image:1oaf.gif|left|200px]]<br /><applet load="1oaf" size="350" color="white" frame="true" align="right" spinBox="true" 
caption="1oaf, resolution 1.4&Aring;" />
'''ASCOBATE PEROXIDASE FROM SOYBEAN CYTOSOL IN COMPLEX WITH ASCORBATE'''<br />

==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 [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Glycine_max Glycine max] with <scene name='pdbligand=NA:'>NA</scene>, <scene name='pdbligand=HEM:'>HEM</scene> and <scene name='pdbligand=ASC:'>ASC</scene> 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] Known structural/functional Site: <scene name='pdbsite=AC1:Asc+Binding+Site+For+Chain+A'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OAF 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:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12640445 12640445]
[[Category: Glycine max]]
[[Category: L-ascorbate peroxidase]]
[[Category: Single protein]]
[[Category: Moody, P C.E.]]
[[Category: Raven, E L.]]
[[Category: Sharp, K H.]]
[[Category: ASC]]
[[Category: HEM]]
[[Category: NA]]
[[Category: ascorbate peroxidase]]
[[Category: heme peroxidase]]
[[Category: peroxide scavenge]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:15:18 2008''