title: Malate utilization by a group D Streptococcus: physiological properties and purification of an inducible malic enzyme.
abstract: Growth of Streptococcus faecalis in the presence of l-malate resulted in the induction of a "malic enzyme" [l-malate:nicotinamide adenine dinucleotide (NAD) oxidoreductase (decarboxylating), E.C. 1.1.1.39]. Synthesis of the malic enzyme did not appear to be subject to catabolite repression by intermediate products of glucose or fructose dissimilation. However, malate utilization was inhibited during growth in the presence of glucose or fructose. The purified enzyme was specific for malate as substrate and NAD as cofactor. Mn(+2) or Mg(+2) was required for optimal activity and NH(4)Cl stimulated the reaction rate. Several lines of indirect evidence suggested that the streptococcal malic enzyme was involved primarily with energy production and not biosynthesis.
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D002474:Cell-Free System; D004589:Electrophoresis, Disc; D013293:Enterococcus faecalis / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D004790:Enzyme Induction; D004794:Enzyme Repression; D005632:Fructose / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D008291:Malate Dehydrogenase; D008293:Malates / Q000378:metabolism; D008345:Manganese / Q000494:pharmacology; D009243:NAD
chemical_list: D008293:Malates; D000643:Ammonium Chloride; D009243:NAD; D005632:Fructose; D008345:Manganese; D008291:Malate Dehydrogenase; D008274:Magnesium; D005947:Glucose