title: Structural basis for nitrous oxide generation by bacterial nitric oxide reductases.
abstract: The crystal structure of the bacterial nitric oxide reductase (cNOR) from Pseudomonas aeruginosa is reported. Its overall structure is similar to those of the main subunit of aerobic and micro-aerobic cytochrome oxidases (COXs), in agreement with the hypothesis that all these enzymes are members of the haem-copper oxidase superfamily. However, substantial structural differences between cNOR and COX are observed in the catalytic centre and the delivery pathway of the catalytic protons, which should be reflected in functional differences between these respiratory enzymes. On the basis of the cNOR structure, we propose a possible reaction mechanism of nitric oxide reduction to nitrous oxide as a working hypothesis.
authors.affiliation: RIKEN SPring-8 Center, Sayo, Hyogo, Japan. yshiro@riken.jp
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Shiro
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sugimoto
authors.forename: Takehiko
authors.initials: T
authors.lastname: Tosha
authors.forename: Shingo
authors.initials: S
authors.lastname: Nagano
authors.forename: Tomoya
authors.initials: T
authors.lastname: Hino
mesh_terms: D018360:Crystallography, X-Ray; D008958:Models, Molecular; D009569:Nitric Oxide / Q000378:metabolism*; D009609:Nitrous Oxide / Q000378:metabolism*; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000378:metabolism*
chemical_list: D009569:Nitric Oxide; D010088:Oxidoreductases; C034747:nitric-oxide reductase; D009609:Nitrous Oxide