Current understandings of colibactin regulation

Abstract

The biosynthetic machinery for the production of colibactin is encoded by 19 genes (<i>clbA - S</i>) within the <i>pks</i> pathogenicity island harboured by many <i>E. coli</i> of the B2-phylogroup. Colibactin is a potent genotoxic metabolite which causes DNA-damage and which has potential roles in microbial competition and fitness of <i>pks</i>+ bacteria. Colibactin has also been strongly implicated in the development of colorectal cancer. Given the genotoxicity of colibactin and the metabolic cost of its synthesis, the regulatory system governing the <i>clb</i> cluster is accordingly highly complex, and many of the mechanisms remain to be elucidated. In this review we summarise the current understanding of regulation of colibactin biosynthesis by internal molecular components and how these factors are modulated by signals from the external environment.