In enzymology, D-lactate dehydrogenase (cytochrome c-553) () is an enzyme that catalyzes the chemical reaction
The substrate of this enzyme is (R)-lactic acid, which is acted on by two equivalents of the cofactor, ferrocytochrome c-553, which oxidises the hydroxy group to a keto group, giving pyruvic acid, while the cofactor's iron is reduced.
This enzyme belongs to the family of oxidoreductases, to be specific those acting on the CH-OH group of donor with a cytochrome as acceptor. The systematic name of this enzyme class is (R)-lactate:ferricytochrome-c-553 2-oxidoreductase. This enzyme participates in pyruvate metabolism.