1HJ5

Cytochrome cd1 Nitrite Reductase, reoxidised enzyme

Summary for 1HJ5

• Entry DOI: 10.2210/pdb1hj5/pdb
• Related: 1AOF 1HJ3 1HJ4
• Descriptor: Nitrite reductase, HEME C, HEME D, ... (6 entities in total)
• Functional Keywords: enzyme, nitrite reductase, oxidoreductase
• Biological source: Paracoccus pantotrophus (Thiosphaera pantotropha)
• Total number of polymer chains: 2
• Total formula weight: 128603.74

Authors

Sjogren, T.,Hajdu, J. (deposition date: 2001-01-08, release date: 2001-01-16, Last modification date: 2024-10-23)

Primary citation

Sjogren, T.,Hajdu, J.
Structure of the bound dioxygen species in the cytochrome oxidase reaction of cytochrome cd1 nitrite reductase.
J. Biol. Chem., 276:13072-13076, 2001

PubMed Abstract: 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.

PubMed: 11278884
DOI: 10.1074/jbc.M011312200

Experimental method

X-RAY DIFFRACTION (1.46 Å)