HMM Summary Page: TIGR01756

Functionlactate dehydrogenase
Trusted Cutoff486.25
Domain Trusted Cutoff486.25
Noise Cutoff486.05
Domain Noise Cutoff486.05
Isology Typeequivalog
EC Number1.1.1.27
HMM Length313
AuthorSelengut J
Entry DateDec 3 2002 9:26PM
Last ModifiedFeb 14 2011 3:27PM
CommentThis model represents a family of protist lactate dehydrogenases which have aparrently evolved from a recent protist malate dehydrogenase ancestor [1]. Lactate dehydrogenase converts the hydroxyl at C-2 of lactate to a carbonyl in the product, pyruvate. The preference of this enzyme for NAD or NADP has not been determined. A critical residue in malate dehydrogenase, arginine-91 (T. vaginalis numbering) has been mutated to a leucine, eliminating the positive charge which complemeted the carboxylate in malate which is absent in lactate. Several other more subtle changes are proposed to make the active site smaller to accomadate the less bulky lactate molecule.
ReferencesRN [1] RM PMID: 10339579 RT Convergent evolution of Trichomonas vaginalis lactate dehydrogenase from malate dehydrogenase. RA Wu G, Fiser A, ter Kuile B, Sali A, Muller M. RL Proc Natl Acad Sci U S A 1999 May 25;96(11):6285-90