L-lactate dehydrogenases are metabolic enzymes which catalyse the conversion of L-lactate to pyruvate, the last step in anaerobic glycolysis. L-2-hydroxyisocaproate dehydrogenases are also members of the family. Malate dehydrogenases catalyse the interconversion of malate to oxaloacetate. The enzyme participates in the citric acid cycle. L-lactate dehydrogenase is 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.

1: Structural basis of substrate specificity in malate dehydrogenases: crystal structure of a ternary complex of porcine cytoplasmic malate dehydrogenase, alpha-ketomalonate and tetrahydoNAD. Chapman AD, Cortes A, Dafforn TR, Clarke AR, Brady RL; J Mol Biol 1999;285:703-712. PMID:10075524

2: Molecular evolution within the L-malate and L-lactate dehydrogenase super-family. Madern D; J Mol Evol 2002;54:825-840. PMID:12029364