title: Glucokinase-deficient mutant of Penicillium chrysogenum is derepressed in glucose catabolite regulation of both beta-galactosidase and penicillin biosynthesis.
abstract: One glucokinase-deficient mutant (glk1) of Penicillium chrysogenum AS-P-78 was isolated after germ tube-emitting spores were mutated with nitrosoguanidine and selected for growth on lactose-containing medium in the presence of inhibitory concentrations of D-2-deoxyglucose (3 mM). Penicillin biosynthesis was greatly reduced (55%) in D-glucose-grown cultures of the parental strain, but this sugar had no repressive effect on the rate of penicillin biosynthesis in the mutant glk1. This mutant was deficient in ATP-dependent glucokinase and showed a greatly reduced uptake of D-glucose. The parental strain P. chrysogenum AS-P-78 showed in vitro ATP-dependent phosphorylating activities of D-glucose, D-2-deoxyglucose, and D-galactose. The glk1 mutant was deficient in the in vitro phosphorylation of D-glucose and D-2-deoxyglucose but retained a normal D-galactose-phosphorylating activity. D-Glucose repressed both beta-galactosidase and isopenicillin-N-synthase but not acyl coenzyme A:6-aminopenicillanic acid acyltransferase in the parental strain. The glucokinase-deficient mutant was simultaneously derepressed in carbon catabolite regulation of beta-galactosidase and isopenicillin-N-synthase, suggesting that a common regulatory mechanism is involved in carbon catabolite regulation of both sugar utilization and penicillin biosynthesis.
mesh_terms: D002244:Carbon / Q000378:metabolism; D005696:Galactosidases / Q000378:metabolism*; D005941:Glucokinase / Q000172:deficiency*; D005947:Glucose / Q000378:metabolism* / Q000502:physiology; D009154:Mutation; D010406:Penicillins / Q000096:biosynthesis*; D010407:Penicillium / Q000201:enzymology*; D010408:Penicillium chrysogenum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D010766:Phosphorylation; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D010406:Penicillins; D002244:Carbon; D005941:Glucokinase; D005696:Galactosidases; D001616:beta-Galactosidase; D005947:Glucose