1hj4
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Reduction of dioxygen to water is a key process in aerobic life, but | + | Reduction of dioxygen to water is a key process in aerobic life, but atomic details of this reaction have been elusive because of difficulties in observing active oxygen intermediates by crystallography. Cytochrome cd(1) is a bifunctional enzyme, capable of catalyzing the one-electron reduction of nitrite to nitric oxide, and the four-electron reduction of dioxygen to water. The latter is a cytochrome oxidase reaction. Here we describe the structure of an active dioxygen species in the enzyme captured by cryo-trapping. The productive binding mode of dioxygen in the active site is very similar to that of nitrite and suggests that the catalytic mechanisms of oxygen reduction and nitrite reduction are closely related. This finding has implications to the understanding of the evolution of oxygen-reducing enzymes. Comparison of the dioxygen complex to complexes of cytochrome cd(1) with stable diatomic ligands shows that nitric oxide and cyanide bind in a similar bent conformation to the iron as dioxygen whereas carbon monoxide forms a linear complex. The significance of these differences is discussed. |
==About this Structure== | ==About this Structure== | ||
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[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''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 13:01:48 2008'' |
Revision as of 11:01, 21 February 2008
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CYTOCHROME CD1 NITRITE REDUCTASE, X-RAY REDUCED DIOXYGEN COMPLEX
Overview
Reduction of dioxygen to water is a key process in aerobic life, but atomic details of this reaction have been elusive because of difficulties in observing active oxygen intermediates by crystallography. Cytochrome cd(1) is a bifunctional enzyme, capable of catalyzing the one-electron reduction of nitrite to nitric oxide, and the four-electron reduction of dioxygen to water. The latter is a cytochrome oxidase reaction. Here we describe the structure of an active dioxygen species in the enzyme captured by cryo-trapping. The productive binding mode of dioxygen in the active site is very similar to that of nitrite and suggests that the catalytic mechanisms of oxygen reduction and nitrite reduction are closely related. This finding has implications to the understanding of the evolution of oxygen-reducing enzymes. Comparison of the dioxygen complex to complexes of cytochrome cd(1) with stable diatomic ligands shows that nitric oxide and cyanide bind in a similar bent conformation to the iron as dioxygen whereas carbon monoxide forms a linear complex. The significance of these differences is discussed.
About this Structure
1HJ4 is a Single protein structure of sequence from Paracoccus pantotrophus with , , and as ligands. Known structural/functional Sites: , , and . Full crystallographic information is available from OCA.
Reference
Structure of the bound dioxygen species in the cytochrome oxidase reaction of cytochrome cd1 nitrite reductase., Sjogren T, Hajdu J, J Biol Chem. 2001 Apr 20;276(16):13072-6. Epub 2001 Jan 26. PMID:11278884
Page seeded by OCA on Thu Feb 21 13:01:48 2008
Categories: Paracoccus pantotrophus | Single protein | Hajdu, J. | Sjogren, T. | DHE | GOL | HEC | SO4 | Enzyme | Nitrite reductase | Oxidoreductase
