title: Induction of haemolytic activity in Escherichia coli by the slyA gene product.
abstract: The Salmonella typhimurium protein SlyA(ST), originally described as a cytolysin, shows sequence similarities to several known bacterial regulatory proteins. A homologue to the Slya(ST) gene has been localised to min 37 of the Escherichia coil K-12 chromosome and has been designated SlyA(EC). When introduced in trans on a plasmid, the SlyA(EC) gene conferred a haemolytic phenotype on wild-type but not clyA-knockout strains of E. coli K-12. The clyA gene encodes a novel haemolysin that is not expressed by wild-type E. coli under tested laboratory conditions. Western and Northern blot analyses, and DNA-band-shift assays support a model whereby the SlyA(EC) protein activates clyA expression by binding to the clyA promoter region, thereby supporting the sequence similarity data in suggesting that SlyA(ST) is a haemolysin activator rather than being a haemolysin per se.
authors.affiliation: Department of Microbiology, Umeå University, Umeå, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Oscarsson
authors.forename: Y
authors.initials: Y
authors.lastname: Mizunoe
authors.forename: B E
authors.initials: BE
authors.lastname: Uhlin
authors.forename: D J
authors.initials: DJ
authors.lastname: Haydon
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D015964:Gene Expression Regulation, Bacterial; D006460:Hemolysin Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D006461:Hemolysis; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014157:Transcription Factors
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006460:Hemolysin Proteins; D014157:Transcription Factors; C056785:salmolysin