Fig. 1 |. Structures of precolibactin-969 (1), colibactin-645 (2) and other structures discussed in this manuscript.
The adenine adduct 4 was identified in the digestion mixture of DNA treated with clb+ E. coli and in colonic epithelial cells of mice colonized by the bacteria. The adduct 4 forms by nucleotide addition to the electrophilic cyclopropane 3 and/or clb products of greater complexity. Alternative structure 5 advanced for colibactin. The diadenine adduct 6 was identified in linearized pUC19 DNA and cellular genomic DNA that had been exposed to clb+ E. coli.