Download MendeleyHigh-affinity inhibitors of Zymomonas mobilis tRNA-guanine transglycosylase through convergent optimization.
Barandun, L.J., Immekus, F., Kohler, P.C., Ritschel, T., Heine, A., Orlando, P., Klebe, G., Diederich, F.(2013) Acta Crystallogr D Biol Crystallogr 69: 1798-1807
- PubMed: 23999303 Search on PubMed
- DOI: https://doi.org/10.1107/S0907444913014509
- Primary Citation Related Structures:
4GG9, 4GH1, 4GH3, 4GI4, 4GIY, 4GKT - PubMed Abstract:
The tRNA-modifying enzyme tRNA-guanine transglycosylase (TGT) has been recognized as a drug target for the treatment of the foodborne illness shigellosis. The active site of TGT consists of three pockets: the central guanine/preQ1 recognition site and the ribose-33 and ribose-34 pockets. In previous work, lin-benzoguanines and lin-benzohypoxanthines, which differ by the presence of an exocyclic NH2 group in the former and its absence in the latter, were used as central scaffolds that bind to the guanine/preQ1 recognition site and allow suitable functionalization along exit vectors targeting the two ribose pockets. The substituents for both of these two pockets have been optimized individually. Here, a series of bifunctionalized inhibitors that occupy both ribose pockets are reported for the first time. Dissociation constants Kd down to the picomolar range were measured for the bifunctionalized lin-benzoguanine-based ligands and Kd values in the nanomolar range were measured for the corresponding lin-benzohypoxanthine-based ligands. The binding mode of all inhibitors was elucidated by X-ray crystal structure analysis. A remarkable influence of the crystallization protocol on the solvation pattern in the solid state and the residual mobility of the bound ligands was observed.
- Laboratorium für Organische Chemie, ETH Zürich, Hönggerberg, HCI, 8093 Zurich, Switzerland.
Organizational Affiliation:
