L-lactate dehydrogenases are metabolic enzymes which catalysethe conversion of L-lactate to pyruvate, the last step inanaerobic glycolysis. L-2-hydroxyisocaproate dehydrogenases arealso members of the family. Malate dehydrogenases catalyse theinterconversion of malate to oxaloacetate. The enzymeparticipates in the citric acid cycle. L-lactate dehydrogenaseis also found as a lens crystallin in bird and crocodile eyes.N-terminus (this family) is a Rossmann NAD-binding fold.C-terminus is an unusual alpha+beta fold.