Structure of heme d₁-free cd₁ nitrite reductase NirS.

ABSTRACT: A key step in anaerobic nitrate respiration is the reduction of nitrite to nitric oxide, which is catalysed by the cd₁ nitrite reductase NirS in, for example, the Gram-negative opportunistic pathogen Pseudomonas aeruginosa. Each subunit of this homodimeric enzyme consists of a cytochrome c domain and an eight-bladed β-propeller that binds the uncommon isobacteriochlorin heme d₁ as an essential part of its active site. Although NirS has been well studied mechanistically and structurally, the focus of previous studies has been on the active heme d₁-bound form. The heme d₁-free form of NirS reported here, which represents a premature state of the reductase, adopts an open conformation with the cytochrome c domains moved away from each other with res

SUBMITTER: Klunemann T 

PROVIDER: S-EPMC7278500 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature