Download MendeleyStructural basis of colibactin activation by the ClbP peptidase.
Velilla, J.A., Volpe, M.R., Kenney, G.E., Walsh Jr., R.M., Balskus, E.P., Gaudet, R.(2023) Nat Chem Biol 19: 151-158
- PubMed: 36253550
- DOI: https://doi.org/10.1038/s41589-022-01142-z
- PubMed Abstract:
Colibactin, a DNA cross-linking agent produced by gut bacteria, is implicated in colorectal cancer. Its biosynthesis uses a prodrug resistance mechanism: a non-toxic precursor assembled in the cytoplasm is activated after export to the periplasm. This activation is mediated by ClbP, an inner-membrane peptidase with an N-terminal periplasmic catalytic domain and a C-terminal three-helix transmembrane domain. Although the transmembrane domain is required for colibactin activation, its role in catalysis is unclear. Our structure of full-length ClbP bound to a product analog reveals an interdomain interface important for substrate binding and enzyme stability and interactions that explain the selectivity of ClbP for the N-acyl-D-asparagine prodrug motif. Based on structural and biochemical evidence, we propose that ClbP dimerizes to form an extended substrate-binding site that can accommodate a pseudodimeric precolibactin with its two terminal prodrug motifs in the two ClbP active sites, thus enabling the coordinated activation of both electrophilic warheads.
Organizational Affiliation:
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
