a (2S)-2-hydroxycarboxylate + NAD(P)+ = a 2-oxocarboxylate + NAD(P)H + H+
MdhII; lactate/malate dehydrogenase
The enzyme from the archaeon Methanocaldococcus jannaschii catalyses the reversible oxidation of (2R)-3-sulfolactate and (S)-malate to 3-sulfopyruvate and oxaloacetate, respectively (note that (2R)-3-sulfolactate has the same stereochemical configuration as (2S)-2-hydroxycarboxylates) . The enzyme can use both NADH and NADPH, although activity is higher with NADPH [1-3]. The oxidation of (2R)-3-sulfolactate was observed only in the presence of NADP+ . The same organism also possesses an NAD+-specific enzyme with similar activity, cf. EC 126.96.36.1997, L-2-hydroxycarboxylate dehydrogenase (NAD+).
Graupner, M., Xu, H. and White, R.H. Identification of an archaeal 2-hydroxy acid dehydrogenase catalyzing reactions involved in coenzyme biosynthesis in methanoarchaea. J. Bacteriol.182 (2000) 3688–3692. [DOI] [PMID: 10850983]
Lee, B.I., Chang, C., Cho, S.J., Eom, S.H., Kim, K.K., Yu, Y.G. and Suh, S.W. Crystal structure of the MJ0490 gene product of the hyperthermophilic archaebacterium Methanococcus jannaschii, a novel member of the lactate/malate family of dehydrogenases. J. Mol. Biol.307 (2001) 1351–1362. [DOI] [PMID: 11292347]
Madern, D. The putative L-lactate dehydrogenase from Methanococcus jannaschii is an NADPH-dependent L-malate dehydrogenase. Mol. Microbiol.37 (2000) 1515–1520. [DOI] [PMID: 10998181]