title: Cloning and amplified expression in Streptomyces lividans of a gene encoding extracellular beta-lactamase from Streptomyces albus G.
abstract: A 4.9-kb DNA fragment containing the bla gene for the extracellular beta-lactamase (BLA) of Streptomyces albus G was cloned in Streptomyces lividans using the conjugative, low-copy-number plasmid pIJ61 as vector. No expression of bla was observed when this DNA fragment was introduced into Escherichia coli HB101 on a plasmid vector. A 1.5-kb PstI-SstI fragment containing the bla gene was cloned in S. lividans on the nonconjugative, high-copy-number plasmid pIJ702. A tenfold higher yield of BLA was obtained from S. lividans carrying this plasmid than from S. albus G grown under optimal production conditions. The BLA from the clone reacts with beta-iodopenicillanate according to a branched pathway which is characteristic of the original S. albus G BLA enzyme.
mesh_terms: D003001:Cloning, Molecular; D005110:Extracellular Space / Q000201:enzymology; D005784:Gene Amplification; D005822:Genetic Vectors; D010397:Penicillanic Acid / Q000494:pharmacology / Q000031:analogs & derivatives; D010957:Plasmids; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics*; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D065093:beta-Lactamase Inhibitors; D010397:Penicillanic Acid; C031528:6-iodopenicillanic acid; D001618:beta-Lactamases