Ligand-induced distortion of an active site in thymidylate synthase upon binding anticancer drug 1843U89.Weichsel, A., Montfort, W.R.
(1995) Nat Struct Biol 2: 1095-1101
- PubMed: 8846221
- DOI: https://doi.org/10.1038/nsb1295-1095
- Primary Citation of Related Structures:
- PubMed Abstract:
The anticancer drug 1843U89 inhibits thymidylate synthase (TS) at sub-nanomolar concentrations and is undergoing clinical trial. The 1.95 A crystal structure of Escherichia coli TS bound to the drug and dUMP reveals that the 1843U89 binding surface includes a hydrophobic patch that is normally buried. To reach this patch, 1843U89 inserts into the wall of the TS active site, resulting in a severe local distortion of the protein. In this new conformation, active-site groups that normally bind to the catalytic cofactor methylene-tetrahydrofolate instead bind to 1843U89 in new ways. This structure provides a rare example of a protein that can bind tightly to distinct substances using a single, flexible, binding surface. This has implications for drug design, as 1843U89 could not have been obtained from current structure-based approaches.
Department of Biochemistry, University of Arizona Tucson 85721, USA.