title: Cloning and heterologous expression of the phenazine biosynthetic locus from Pseudomonas aureofaciens 30-84.
abstract: Pseudomonas aureofaciens strain 30-84 suppresses take-all disease of wheat caused by Gaeumannomyces graminis var. tritici. Three antibiotics, phenazine-1-carboxylic acid, 2-hydroxyphenazine-1-carboxylic acid, and 2-hydroxyphenazine, were responsible for disease suppression. Tn5-induced mutants deficient in production of one or more of the antibiotics (Phz-) were significantly less suppressive than the parental strain. Cosmids pLSP259 and pLSP282 from a genomic library of strain 30-84 restored phenazine production and fungal inhibition to 10 different Phz- mutants. Sequences required for production of the phenazines were localized to a segment of approximately 2.8 kilobases that was present in both cosmids. Expression of this locus in Escherichia coli required the introduction of a functional promoter, was orientation-specific, and resulted in the production of all three phenazine antibiotics. These results strongly suggest that the cloned sequences encode a major portion of the phenazine biosynthetic pathway.
authors.affiliation: Agricultural Research Service, U.S. Department of Agriculture, Washington State University, Pullman 99164-6430.
authors.forename: L S
authors.initials: LS
authors.lastname: Pierson
authors.forename: L S
authors.initials: LS
authors.lastname: Thomashow
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism*; D004252:DNA Mutational Analysis; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D016254:Mutagenesis, Insertional; D010619:Phenazines / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D010935:Plant Diseases / Q000382:microbiology; D011549:Pseudomonas / Q000235:genetics*; D014908:Triticum / Q000382:microbiology
chemical_list: D000935:Antifungal Agents; D004251:DNA Transposable Elements; D010619:Phenazines