A pan-bacterial lineage of proteins. Nitrate assimilation protein, NarQ, [1] and FdhD (Swiss:P32177) are required for formate dehydrogenase activity. Structurally, they possess a deaminase fold with a characteristic binding pocket, suggesting that they might bind a nucleotide or related molecule allosterically to regulate the formate dehydrogenase catalytic subunit [2].

1: Identification and isolation of a gene required for nitrate assimilation and anaerobic growth of Bacillus subtilis. Glaser P, Danchin A, Kunst F, Zuber P, Nakano MM; J Bacteriol 1995;177:1112-1115. PMID:7860592

2: Evolution of the deaminase fold and multiple origins of eukaryotic editing and mutagenic nucleic acid deaminases from bacterial toxin systems. Iyer LM, Zhang D, Rogozin IB, Aravind L; Nucleic Acids Res. 2011; [Epub ahead of print] PMID:21890906