title: DD-carboxypeptidase-transpeptidase and killing site of beta-lactam antibiotics in Streptomyces strains R39, R61, and K11.
abstract: Additional evidence is given that in Streptomyces strains R39, R61, and K11 the same enzyme performs dd-carboxypeptidase and transpeptidase activities and that this enzyme is the killing site of beta-lactam antibiotics. With strain R61, it was found that the exocellular enzyme has a sensitivity towards some antibiotics different from that of the membrane-bound enzyme. Under the growth conditions used in the present investigations, beta-lactamase activity was not involved in susceptibility to beta-lactam antibiotics.
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002268:Carboxypeptidases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010405:Penicillinase / Q000378:metabolism; D013302:Streptomyces / Q000187:drug effects* / Q000201:enzymology; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D000217:Acyltransferases; D002268:Carboxypeptidases; D010405:Penicillinase