title: Expression of gamma-hemolysin regulated by sae in Staphylococcus aureus strain Smith 5R.
abstract: Staphylococcus aureus strain Smith 5R produces a two-component pore-forming toxin and forms a rough-surfaced colony with hemolytic haloes on human red blood cell plates (R[+]). Serial subcultures of the strain in broth caused the appearance of gamma-hemolysin negative variants with a smooth colony shape (S[-]), and the S[-] valiant became predominant in culture. The R[+] strain, in which agrA is naturally disrupted by an insertion of IS1181, produced high levels of gamma-hemolysin. In the S[-] variant, expression of both hlg and lukS-F mRNAs was strongly reduced. Nucleotide sequencing of the sae locus revealed that all isolated S[-] variants had spontaneous mutations in the sae locus. Recovery of gamma-hemolysin productivity in S[-] by transformation of the wild-type sae allele strongly suggested that the expression of gamma-hemolysin is positively regulated by sae in an agr-independent manner.
authors.affiliation: Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Fuminori
authors.initials: F
authors.lastname: Kato
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kamio
authors.forename: Jun
authors.initials: J
authors.lastname: Kaneko
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D006460:Hemolysin Proteins; D006461:Hemolysis; D006801:Humans; D066298:In Vitro Techniques; D012329:RNA, Bacterial / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D013211:Staphylococcus aureus / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D006460:Hemolysin Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; C037956:gamma-hemolysin, Staphylococcus aureus