title: Glucose regulation of cephamycin biosynthesis in Streptomyces lactamdurans is exerted on the formation of alpha-aminoadipyl-cysteinyl-valine and deacetoxycephalosporin C synthase.
abstract: Glucose exerted a concentration-dependent negative regulation on the biosynthesis of cephamycin C by Streptomyces lactamdurans. Formation of the cephamycin precursor delta(alpha-aminoadipyl)-cysteinyl-valine was greatly decreased by excess glucose. The ring-expanding enzyme deacetoxycephalosporin C synthase was strongly repressed by glucose in vivo. Isopenicillin N synthase (cyclase) and isopenicillin N epimerase were not repressed by glucose. However, the activity of isopenicillin N synthase was inhibited in vitro by glucose 6-phosphate, and the activity of deacetoxycephalosporin C synthase was inhibited by inorganic phosphate, glucose 6-phosphate, fructose 2,6-diphosphate and fructose 1,6-diphosphate. The intracellular cAMP content decreased as growth proceeded and remained lower in glucose-supplemented cells than in control cultures. cAMP did not seem to be involved in glucose control of cephamycin biosynthesis.
mesh_terms: D000591:Amino Acid Isomerases / Q000378:metabolism; D001426:Bacterial Proteins; D002513:Cephamycins / Q000096:biosynthesis*; D004798:Enzymes / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D019751:Intramolecular Transferases; D007535:Isomerases / Q000096:biosynthesis*; D007700:Kinetics; D009842:Oligopeptides / Q000096:biosynthesis*; D010088:Oxidoreductases; D046915:Penicillin-Binding Proteins; D010710:Phosphates / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002513:Cephamycins; D004798:Enzymes; D009842:Oligopeptides; D046915:Penicillin-Binding Proteins; D010710:Phosphates; C011638:5-(2-aminoadipyl)cysteinylvaline; D010088:Oxidoreductases; C038370:isopenicillin N synthetase; D007535:Isomerases; D000591:Amino Acid Isomerases; C040886:isopenicillin N epimerase; D019751:Intramolecular Transferases; C038371:deacetoxycephalosporin C synthetase; D005947:Glucose