Toxin genes on pathogenicity islands: impact for microbial evolution

• Published in: International journal of medical microbiology 2000-10, Vol.290 (4), p.307-311
• Main Authors: Dobrindt, U., Janke, B., Piechaczek, K., Nagy, G., Ziebuhr, W., Fischer, G., Schierhorn, A., Hecker, M., Blum-Oehler, G., Hacker, J.
• Format: Article
• Language: English
• Subjects: Bacterial Toxins - genetics; Bacteriology; Biological and medical sciences; Escherichia coli - genetics; Escherichia coli - pathogenicity; Fundamental and applied biological sciences. Psychology; Genetics; Hemolysin Proteins - genetics; leuX; microbial evolution; Microbiology; minor tRNA; Mutation; Pathogenicity islands; Proteome; RNA, Transfer - physiology; uropathogenic E. coli; Virulence - genetics; α-hemolysin
• ISSN: 1438-4221; 1618-0607
• DOI: 10.1016/S1438-4221(00)80028-4

Toxin-specific genes are often located on mobile genetic elements such as phages, plasmids and pathogenicity islands (PAIs). The uropathogenic E. coli strain 536 carries two α-hemolysin gene clusters, which are part of the pathogenicity islands I 536 and II 536, respectively. Using different genetic techniques, two additional PAIs were identified in the genome of the E. coli strain 536, and it is likely that further PAIs are located on the genome of this strain. Pathogenicity islands are often associated with tRNA genes. In the case of the E. coli strain 536, the PAI-associated tRNA gene leuX, which encodes a minor leucyl-tRNA, affects the expression of various virulence traits including α-hemolysin production. The exact mode of action of the tRNA 5 Leu-dependent gene expression has to be identified in the future.