CcNiR
Your Heading Here ('ccNiR')Your Heading Here ('ccNiR')
| Cytochrome c nitrite reductase is a multicenter enzyme that uses a five-coordinated heme to perform the reduction of nitrite to ammonium in a six-electron transfer reaction [1]
| ||||||||||
Cytochrome c nitrite reductase is a multicenter enzyme that uses a five-coordinated heme to perform the reduction of nitrite to ammonium in a six-electron transfer reaction. In the sulfate reducing bacterium Desulfovibrio desulfuricans ATCC 27774, the enzyme is purified as a NrfA2NrfH complex that houses 14 hemes.
The catalytic reaction occurs at a high-spin (5-coordinated) heme that is located at a pentahemic subunit of 61 kDa which is strongly bound to its physiological electron donor, a smaller hydrophobic polypeptide tetrahemic of 19 kDa, composed of 4 c-types hemes; in vitro, the protein complexes associate each other forming huge aggregates (min. 890 kDa).
- ↑ Almeida MG, Macieira S, Goncalves LL, Huber R, Cunha CA, Romao MJ, Costa C, Lampreia J, Moura JJ, Moura I. The isolation and characterization of cytochrome c nitrite reductase subunits (NrfA and NrfH) from Desulfovibrio desulfuricans ATCC 27774. Re-evaluation of the spectroscopic data and redox properties. Eur J Biochem. 2003 Oct;270(19):3904-15. PMID:14511372