title: The putative malate/lactate dehydrogenase from Pseudomonas putida is an NADPH-dependent delta1-piperideine-2-carboxylate/delta1-pyrroline-2-carboxylate reductase involved in the catabolism of D-lysine and D-proline.
abstract: A Pseudomonas putida ATCC12633 gene, dpkA, encoding a putative protein annotated as malate/L-lactate dehydrogenase in various sequence data bases was disrupted by homologous recombination. The resultant dpkA(-) mutant was deprived of the ability to use D-lysine and also D-proline as a sole carbon source. The dpkA gene was cloned and overexpressed in Escherichia coli, and the gene product was characterized. The enzyme showed neither malate dehydrogenase nor lactate dehydrogenase activity but catalyzed the NADPH-dependent reduction of such cyclic imines as Delta(1)-piperideine-2-carboxylate and Delta(1)-pyrroline-2-carboxylate to form L-pipecolate and L-proline, respectively. NADH also served as a hydrogen donor for both substrates, although the reaction rates were less than 1% of those with NADPH. The reverse reactions were also catalyzed by the enzyme but at much lower rates. Thus, the enzyme has dual metabolic functions, and we named the enzyme Delta(1)-piperideine-2-carboxylate/Delta(1)-pyrroline-2-carboxylate reductase, the first member of a novel subclass in a large family of NAD(P)-dependent oxidoreductases.
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Muramatsu
authors.forename: Hisaaki
authors.initials: H
authors.lastname: Mihara
authors.forename: Ryo
authors.initials: R
authors.lastname: Kakutani
authors.forename: Mari
authors.initials: M
authors.lastname: Yasuda
authors.forename: Makoto
authors.initials: M
authors.lastname: Ueda
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kurihara
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Esaki
mesh_terms: D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003067:Coenzymes / Q000378:metabolism; D019143:Evolution, Molecular; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism*; D008291:Malate Dehydrogenase / Q000378:metabolism; D009249:NADP / Q000378:metabolism*; D010875:Pipecolic Acids / Q000378:metabolism*; D011392:Proline / Q000378:metabolism*; D016958:Pseudomonas putida / Q000201:enzymology* / Q000235:genetics; D011762:Pyrroline Carboxylate Reductases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D003067:Coenzymes; D010875:Pipecolic Acids; C036512:delta(1)-piperidine-2-carboxylic acid; D009249:NADP; D011392:Proline; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D011762:Pyrroline Carboxylate Reductases; D008239:Lysine