Regulation of aconitase synthesis in Bacillus subtilis: induction, feedback repression, and catabolite repression.
The synthesis of aconitase in Bacillus subtilis wild-type and different citric acid cycle mutants has been studied and the influence of various growth conditions examined. Aconitase is induced by citrate and precursors of citrate and repressed by glutamate. Induction and repression counteract each other, and at equimolar concentrations of citrate and glutamate, aconitase synthesis is unaffected. Induction by citrate can partly overcome catabolite repression of aconitase. Isocitrate dehydrogenase show endogenous induction of aconitase due to citrate accumulation. Leaky mutants defective in citrate synthase and aconitase cannot be induced by citrate, which indicates that they carry a regulatory mutation. The complex regulation of aconitase is discussed with reference to the participation of this enzyme in glutamate biosynthesis and energy metabolism.
D000154:Aconitate Hydratase / Q000096:biosynthesis; D001224:Aspartic Acid / Q000378:metabolism; D001412:Bacillus subtilis / Q000201:enzymology* / Q000378:metabolism; D002474:Cell-Free System; D002950:Citrate (si)-Synthase / Q000096:biosynthesis; D002951:Citrates / Q000378:metabolism; D003470:Culture Media; D004790:Enzyme Induction; D004794:Enzyme Repression; D005246:Feedback; D005650:Fumarates / Q000096:biosynthesis; D005816:Genetic Complementation Test; D005947:Glucose / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D006836:Hydro-Lyases / Q000096:biosynthesis*; D007521:Isocitrate Dehydrogenase / Q000096:biosynthesis; D007655:Ketoglutarate Dehydrogenase Complex / Q000096:biosynthesis; D009154:Mutation; D013385:Succinate Dehydrogenase / Q000096:biosynthesis
D002951:Citrates; D003470:Culture Media; D005650:Fumarates; D005971:Glutamates; D001224:Aspartic Acid; D007521:Isocitrate Dehydrogenase; D007655:Ketoglutarate Dehydrogenase Complex; D013385:Succinate Dehydrogenase; D002950:Citrate (si)-Synthase; D006836:Hydro-Lyases; D000154:Aconitate Hydratase; D005947:Glucose