In enzymology, a formate dehydrogenase (cytochrome-c-553) () is an enzyme that catalyzes the chemical reaction formate + ferricytochrome c-553 CO2 + ferrocytochrome c-553 Thus, the two substrates of this enzyme are formate and ferricytochrome c-553, whereas its two products are CO2 and ferrocytochrome c-553. This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with a cytochrome as acceptor. The systematic name of this enzyme class is formate:ferricytochrome-c-553 oxidoreductase. References EC 1.2.2 Enzymes of unknown structure