Figure 1.

Pks⁺ E. coli induce DNA damage and have a mutational impact leading to cancer formation. Colibactin is synthesized by an assembly line composed of non-ribosomal peptide synthetase (NRPS) and polyketide synthases (PKS) which are encoded by the pks island in E. coli. Colibactin produced by pks⁺ E. coli causes DNA inter-strand cross-links (ICLs) in a cell-to-cell contact dependent manner. ICLs in cellulo are converted into DNA double-strand breaks (DSBs) during the DNA-damage response or by depurination. DNA damages potentially can result in gene mutations which may trigger carcinogenesis.