This domain family is found in bacteria, and is approximately 30 amino acids in length. The family is found in association with Pfam:PF00390, Pfam:PF03949, Pfam:PF01515. There is a conserved AAL sequence motif. There is a single completely conserved residue R that may be functionally important. Malate dehydrogenase is one of the enzymes involved in the citric acid cycle in mitochondria. It converts malate to oxaloacetate using NAD as a cofactor.

1: Molecular adaptation: the malate dehydrogenase from the extreme halophilic bacterium Salinibacter ruber behaves like a non-halophilic protein. Madern D, Zaccai G; Biochimie. 2004;86:295-303. PMID:15194233