NifQ is involved in early stages of the biosynthesis of the iron-molybdenum cofactor (FeMo-co) [1], which is an integral part of the active site of dinitrogenase [2]. The conserved C-terminal cysteine residues may be involved in metal binding [1].

1: Structure of the nifQ gene from Enterobacter agglomerans 333 and its overexpression in Escherichia coli. Siddavattam D, Singh M, Klingmuller W; Mol Gen Genet 1993;239:435-440. PMID:8316214

2: Biosynthesis of the iron-molybdenum cofactor of nitrogenase. Allen RM, Chatterjee R, Madden MS, Ludden PW, Shah VK; Crit Rev Biotechnol 1994;14:225-249. PMID:7954845