Identification, cloning, and initial characterization of rot, a locus encoding a regulator of virulence factor expression in Staphylococcus aureus.
J Bacteriol
; 182(11): 3197-203, 2000 Jun.
Article
en En
| MEDLINE
| ID: mdl-10809700
ABSTRACT
A chromosomal insertion of transposon Tn917 partially restores the expression of protease and alpha-toxin activities to PM466, a genetically defined agr-null derivative of the wild-type Staphylococcus aureus strain RN6390. In co-transduction experiments, transposon-encoded erythromycin resistance and a protease- and alpha-toxin-positive phenotype are transferred at high frequency from mutant strains to agr-null strains of S. aureus. Southern analysis of chromosomal DNA and sequence analysis of DNA flanking the Tn917 insertion site in mutant strains revealed that the transposon interrupted a 498-bp open reading frame (ORF). Similarity searches using a conceptual translation of the ORF identified a region of homology to the known staphylococcal global regulators AgrA and SarA. To verify that the mutant allele conferred the observed phenotype, a wild-type allele of the mutant gene was introduced into the genome of a mutant strain by homologous recombination. The resulting isolates had a restored agr-null phenotype. Virulence factor gene expression in mutant, restored mutant, and wild-type strains was quantified by measuring alpha-toxin activity in culture supernatant fluids and by Northern analysis of the alpha-toxin transcript. We named this ORF rot (for repressor of toxins) (GenBank accession no. AF189239) because of the activity associated with rotTn917 mutant strains.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Proteínas Represoras
/
Staphylococcus aureus
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Proteínas Bacterianas
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Toxinas Bacterianas
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Genes Bacterianos
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Proteínas Hemolisinas
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Idioma:
En
Revista:
J Bacteriol
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos