Formate dehydrogenase N, alpha subunit (Formate-Dh-Na) is a major component of nitrate respiration in bacteria such as in the E. coli formate dehydrogenase N (Fdh-N). Fdh-N is a membrane protein that is a complex of three different subunits and is the major electron donor to the nitrate respiratory chain. Also included in this CD is the Desulfovibrio gigas tungsten formate dehydrogenase, DgW-FDH. In contrast to Fdh-N, which is a functional heterotrimer, DgW-FDH is a heterodimer. The DgW-FDH complex is composed of a large subunit carrying the W active site and one [4Fe-4S] center, and a small subunit that harbors a series of three [4Fe-4S] clusters as well as a putative vacant binding site for a fourth cluster. The smaller subunit is not included in this alignment. This CD (MopB_CT_Formate-Dh-Na-like) is of the conserved molybdopterin_binding C-terminal (MopB_CT) region present in many, but not all, MopB homologs.
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