title: Mutants of Streptomyces cattleya defective in the synthesis of a factor required for thienamycin production.
abstract: Thienamycin non-producing mutants of Streptomydes cattleya were identified that displayed a cross-feeding relationship. A diffusible product from one of these mutants (RK-11) resulted in restoration of thienamycin production when fed to cultures of another mutant (RK-4). In vivo radiolabeling experiments were conducted to test whether the RK-11 mutant produced a late biosynthetic intermediate which contained a carbapenem ring and a cysteaminyl and/or a hydroxyethyl side chain. Both [35S]cystine and [methyl-3H]methionine were used to label the RK-11 product which was then fed to RK-4 cultures. None of the thienamycin subsequently produced by RK-4 converter cells was labeled, implying the lack of either side chain of the thienamycin molecule in the RK-11 product. Further stability studies suggested that the RK-11 product does not contain a carbapenem ring. Additional feeding experiments with RK-4 cells also ruled out the possibility that the RK-11 product is a co-factor necessary for thienamycin production. It is concluded that the RK-11 product may regulate expression of the thienamycin gene cluster.
authors.affiliation: Panlabs, Inc. Bothell, WA 98011.
authors.forename: T
authors.initials: T
authors.lastname: Buchan
authors.forename: C
authors.initials: C
authors.lastname: Roach
authors.forename: C
authors.initials: C
authors.lastname: Ruby
authors.forename: D
authors.initials: D
authors.lastname: Taylor
authors.forename: C
authors.initials: C
authors.lastname: Preisig
authors.forename: C
authors.initials: C
authors.lastname: Reeves
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003553:Cystine / Q000378:metabolism; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008715:Methionine / Q000031:analogs & derivatives / Q000378:metabolism; D009154:Mutation; D013302:Streptomyces / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D013462:Sulfur Radioisotopes; D013696:Temperature; D013845:Thienamycins / Q000096:biosynthesis*; D014316:Tritium
chemical_list: D013462:Sulfur Radioisotopes; D013845:Thienamycins; D014316:Tritium; D003553:Cystine; D005020:Ethyl Methanesulfonate; D008715:Methionine; C038344:methionine methyl ester; C015537:thienamycin