1qks
From Proteopedia
CYTOCHROME CD1 NITRITE REDUCTASE, OXIDISED FORM
Overview
Cytochrome cd1-nitrite reductase is a bifunctional enzyme that catalyzes the one-electron reduction of nitrite to nitric oxide and the four-electron reduction of oxygen to water. The 1.55 A crystal structure of the dimeric enzyme from Thiosphaera pantotropha is reported here. The protein was sequenced from the X-ray structure. Each subunit contains a covalent c heme with two axial His ligands (His-17, His-69) and a unique noncovalent d1 heme ligated by Tyr-25 and His-200. The d1 heme is the mononuclear iron center where both oxygen and nitrite reduction take place. The two types of heme are located in separate domains whose arrangement suggests a mechanism requiring domain movement during catalysis.
About this Structure
1QKS is a Single protein structure of sequence from Paracoccus denitrificans. Full crystallographic information is available from OCA.
Reference
The anatomy of a bifunctional enzyme: structural basis for reduction of oxygen to water and synthesis of nitric oxide by cytochrome cd1., Fulop V, Moir JW, Ferguson SJ, Hajdu J, Cell. 1995 May 5;81(3):369-77. PMID:7736589 Page seeded by OCA on Sat May 3 06:23:45 2008
