Disease relevance of nrfA

• The structural gene, nrfA, for cytochrome c552, which is the terminal reductase of the formate-dependent pathway for nitrite reduction to ammonia, has been located at co-ordinate 4366 on the physical map of the Escherichia coli chromosome [1].

High impact information on nrfA

• The open reading frame immediately downstream of nrfA encodes NrfB, a hydrophilic, penta-haem cytochrome c with an M(r) of 20,714 [2].
• We have now established that nrfA is the first gene in a seven-gene operon, designated the nrf operon, at least five of which are essential for formate-dependent nitrite reduction to ammonia [2].
• In-phase translational fusions to lacZ were used to locate the nrfA translation start, and the transcription start site was found by S1 mapping [1].
• Expression from the FNR-dependent nrfA promoter was almost totally repressed during aerobic growth, partially induced during anaerobic growth in the absence of nitrite or in the presence of nitrate, but fully induced only during anaerobic growth in the presence of nitrite [1].
• The DNA sequence of nrfA encodes a tetrahaem c-type cytochrome with a predicted M(r) for the unprocessed product of 53,788 [1].

Biological context of nrfA

• A plasmid with an in-phase deletion within nrfA directed the synthesis of a truncated haemoprotein of the predicted mass [1].

Associations of nrfA with chemical compounds

• Expression from the nrfA promoter was subject to glucose repression but regulation was independent of the CRP-cAMP complex [1].

References