Formate dehydrogenases are a set of enzymes that catalyse the oxidation of formate to carbon dioxide, donating the electrons to a second substrate, such as NAD+ in formate:NAD+ oxidoreductase (EC 18.104.22.168) or to a cytochrome in formate:ferricytochrome-b1 oxidoreductase (EC 22.214.171.124).
NAD-dependent formate dehydrogenases are important in methylotrophicyeast and bacteria and are vital in the catabolism of C1 compounds such as methanol. The cytochrome-dependent enzymes are more important in anaerobic metabolism in prokaryotes. For example, in E. coli, the formate:ferricytochrome-b1 oxidoreductase is an intrinsic membrane protein with two subunits and is involved in anaerobic nitrate respiration.
The transmembrane domain of the beta subunit of formate dehydrogenase consists of a single transmembrane helix. This domain acts as a transmembrane anchor, allowing the conduction of electrons within the protein.
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