Download MendeleyA Novel Inhibitor That Suspends the Induced Fit Mechanism of UDP-N-acetylglucosamine Enolpyruvyl Transferase (MurA).
Eschenburg, S., Priestman, M.A., Abdul-Latif, F.A., Delachaume, C., Fassy, F., Schonbrunn, E.(2005) J Biol Chem 280: 14070-14075
- PubMed: 15701635
- DOI: https://doi.org/10.1074/jbc.M414412200
- Primary Citation of Related Structures:
1YBG - PubMed Abstract:
MurA (UDP-N-acetylglucosamine enolpyruvyl transferase, EC 2.5.1.7) catalyzes the first committed step in the synthesis of the bacterial cell wall. It is the target of the naturally occurring, broad-spectrum antibiotic fosfomycin. Fosfomycin, an epoxide, is a relatively poor drug because an ever-increasing number of bacteria have developed resistance to fosfomycin. Thus, there is a critical need for the development of novel drugs that target MurA by a different molecular mode of action. We have identified a new scaffold of potent MurA inhibitors, derivatives of 5-sulfonoxy-anthranilic acid, using high-throughput screening. T6361 and T6362 are competitive inhibitors of MurA with respect to the first substrate, UDP-N-acetylglucosamine (UNAG), with a K(i) of 16 microM. The crystal structure of the MurA.T6361 complex at 2.6 angstrom resolution, together with fluorescence data, revealed that the inhibitor targets a loop, Pro112 to Pro121, that is crucial for the structural changes of the enzyme during catalysis. Thus, this new class of MurA inhibitors is not active site-directed but instead obstructs the transition from the open (unliganded) to the closed (UNAG-liganded) enzyme form. The results provide evidence for the existence of a MurA.UNAG collision complex that may be specifically targeted by small molecules different from ground-state analogs of the enzymatic reaction.
Organizational Affiliation:
Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, USA.
