title: Large amplification of a 35-kb DNA fragment carrying two penicillin biosynthetic genes in high penicillin producing strains of Penicillium chrysogenum.
abstract: The isopenicillin N synthase (pcbC) and acyl-CoA:6-APA acyltransferase (penDE) genes of Penicillium chrysogenum were located in a 19.5-kb DNA fragment that had been previously cloned in phage vector EMBL3. This 19.5-kb DNA fragment was mapped with several endonucleases, and the pcbC and penDE genes were located by hybridization with probes corresponding to internal fragments of each gene. A low penicillin producing strain (P. chrysogenum Wis 54-1255) and two high producing strains (AS-P-78 and P2) showed hybridizing fragments of identical sizes in their chromosomes. Dot-blot hybridization of serial dilutions of the total DNA of the three strains showed that the intensity of all the hybridizing bands was much higher in strains AS-P-78 and P2 than in Wis 54-1255. Hybridization of total DNA digestions with probes corresponding to fragments which mapped upstream or downstream of the pcbC-penDE region revealed that a fragment of at least 35 kb DNA has been amplified 9 to 14 fold in the high penicillin producing strains. The amplified region did not include the previously cloned pyrG gene that encodes OMP-decarboxylase, an enzyme involved in pyrimidine biosynthesis.
authors.affiliation: Area de Microbiología, Facultad de Biología, Universidad de León, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Barredo
authors.forename: B
authors.initials: B
authors.lastname: Díez
authors.forename: E
authors.initials: E
authors.lastname: Alvarez
authors.forename: J F
authors.initials: JF
authors.lastname: Martín
mesh_terms: D000217:Acyltransferases / Q000235:genetics*; D015139:Blotting, Southern; D004271:DNA, Fungal / Q000235:genetics*; D004798:Enzymes / Q000235:genetics*; D005784:Gene Amplification; D005800:Genes, Fungal; D010088:Oxidoreductases; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000096:biosynthesis*; D010407:Penicillium / Q000235:genetics*; D010408:Penicillium chrysogenum / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping
chemical_list: D004271:DNA, Fungal; D004798:Enzymes; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D010088:Oxidoreductases; C038370:isopenicillin N synthetase; D000217:Acyltransferases; C018756:acyl-CoA-6-aminopenicillanic acid acyltransferase