title: The chromosomal fur gene regulates the extracellular haemolytic activity encoded by certain hly plasmids.
abstract: The haemolytic activity encoded by thirteen hly-plasmids of different origin and sources was examined as a function of the Fe3+-concentration in E. coli fur+ and E. coli fur- strains, respectively. In E. coli fur+ the relatively low haemolytic activity of five hly-plasmids isolated in Berne and one isolated in Paris was increased significantly under iron-limiting growth conditions. Contrastingly, in E. coli fur- strains containing the same plasmids, a considerably higher amount of secreted haemolysin was detected. This activity could not be further increased by limiting the extracellular iron concentration. Seven other hly-plasmids expressed similar and non-inducible amounts of secreted haemolysin in both E. coli fur+ and E. coli fur- strains. These results indicate that the extracellular haemolytic activity encoded by certain hly-plasmids was controlled by the chromosomally encoded fur gene.
authors.affiliation: Institute of Hygiene and Medical Microbiology, University of Berne, Switzerland.
authors.forename: H M
authors.initials: HM
authors.lastname: Grünig
authors.forename: D
authors.initials: D
authors.lastname: Rutschi
authors.forename: C
authors.initials: C
authors.lastname: Schoch
authors.forename: G
authors.initials: G
authors.lastname: Lebek
mesh_terms: D000818:Animals; D002876:Chromosomes, Bacterial; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000472:pathogenicity; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D006459:Hemolysin Factors; D006460:Hemolysin Proteins / Q000096:biosynthesis* / Q000235:genetics; D006461:Hemolysis; D006801:Humans; D007501:Iron / Q000494:pharmacology; D010957:Plasmids
chemical_list: D006460:Hemolysin Proteins; D007501:Iron