CATH Classification

Domain Context

CATH Clusters

Superfamily C-terminal (heme d1) domain of cytochrome cd1-nitrite reductase
Functional Family Nitrite reductase NirS

Enzyme Information
Hydroxylamine reductase.
based on mapping to UniProt P72181
NH(3) + H(2)O + acceptor = hydroxylamine + reduced acceptor.
-!- Reduced pyocyanine, methylene blue and flavins act as donors for the reduction of hydroxylamine. -!- May be identical to EC
Nitrite reductase (NO-forming).
based on mapping to UniProt P72181
Nitric oxide + H(2)O + ferricytochrome c = nitrite + ferrocytochrome c + 2 H(+).
-!- The reaction is catalyzed by two types of enzymes, found in the perimplasm of denitrifying bacteria. -!- One type comprises proteins containing multiple copper centers, the other a heme protein, cytochrome cd1. -!- Acceptors include c-type cytochromes such as cytochrome c-550 or cytochrome c-551 from Paracoccus denitrificans or Pseudomonas aeruginosa, and small blue copper proteins such as azurin and pseudoazurin. -!- Cytochrome cd1 also has oxidase and hydroxylamine reductase activities. -!- May also catalyze the reaction of EC since this is a well- known activity of cytochrome cd1. -!- Formerly EC, EC and EC

UniProtKB Entries (1)

Paracoccus pantotrophus
Nitrite reductase

PDB Structure

External Links
Primary Citation
Haem-ligand switching during catalysis in crystals of a nitrogen-cycle enzyme.
Williams, P.A., Fulop, V., Garman, E.F., Saunders, N.F., Ferguson, S.J., Hajdu, J.