Induction of haemolytic activity in Escherichia coli by the slyA gene product

Publisher Website
Google Scholar
Abstract
Summary: The Salmonella typhimurium protein SlyAST, originally described as a cytolysin, shows sequence similarities to several known bacterial regulatory proteins. A homologue to the slyASt gene has been localised to min 37 of the Eschericia coli K‐12 chromosome and has been designated slyAEC When introduced in trans on a plasmid, the slyAEC 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 SlyAEC protein activates clyA expression by binding to the clyA promoter region, thereby supporting the sequence similarity data in suggesting that SlyAST is a haemolysin activator rather than being a haemolysin per se.