Null mutations in the essential gene yrfF (mucM) are not lethal in rcsB, yojN or rcsC strains of Salmonella enterica serovar Typhimurium

• Autores: Costa, C.S.; Pettinari, M.J.; Méndez, B.S.; Antón, D.N.
• Año de publicación: 2003
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: FEMS Microbiol. Lett. 2003;222(1):25-32
• Materia: Essential gene; igaA; mucM; Mucoid mutant; rcsC-yojN-rcsB phosphorelay; yrfF; colanic acid; gene product; kanamycin; polysaccharide; protein; protein RcsB; protein RcsC; protein YojN; protein yrfF; unclassified drug; article; bacterial gene; bacterial genome; bacterium colony; controlled study; gene cassette; gene expression; gene function; gene inactivation; gene insertion; gene mutation; genetic analysis; genetic complementation; genetic variability; lethality; molecular cloning; nonhuman; null allele; open reading frame; penicillin resistance; plasmid; priority journal; Salmonella enterica; serotype; wild type; Gale; Salmonella enterica; Salmonella enterica; Salmonella enterica subsp. enterica serovar Typhimurium; Typhimurium
• Institución: Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales

Insertion of factor MudJ in the intergenic region between divergent genes yrfF and yrfE, at centisome 76 in the genome of Salmonella enterica serovar Typhimurium LT2, confers the characteristics recently described for mucM mutants, i.e. mucoidy and resistance to mecillinam. Cloning of the intergenic region plus either the yrfF or the yrfE gene in a multicopy plasmid showed that only the plasmid carrying the yrfF gene complemented mucM mutants, thus suggesting that mucM mutations are in fact yrfF mutations. A null yrfF mutation obtained by insertion of a kanamycin cassette into the yrfF open reading frame (yrfF28::Kan) produced abortive colonies when transduced to a wild-type strain but was normally accepted by rcsB, rcsC or yojN strains. Neither mutations preventing synthesis of the capsular exopolysaccharide colanic acid (cps, galE) nor rcsA mutations, which reduce expression of cps genes, conferred tolerance to the lethal yrfF28::Kan mutation. Spontaneous suppressor mutations arose very frequently in abortive yrfF28::Kan colonies, and all of them affected either rcsC, yojN, or rcsB genes. Thus, the lethal effect caused by inactivation of gene yrfF appears to be mediated by a function that is dependent on the rcsC-yojN-rcsB phosphorelay system but does not involve synthesis of colanic acid. © 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
Fil:Costa, C.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Pettinari, M.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Méndez, B.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Antón, D.N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.