A pan-bacterial lineage of proteins. Nitrate assimilation protein, NarQ, and FdhD are required for formate dehydrogenase activity. Structurally, they possess a deaminase fold with a characteriztic binding pocket, suggesting that they might bind a nucleotide or related molecule allosterically to regulate the formate dehydrogenase catalytic subunit.
Jiyao W et al.(2023). "The conserved domain database in 2023.",