Download MendeleyStructural Characterization of Three Novel Hydroxamate-Based Zinc Chelating Inhibitors of the Clostridium botulinum Serotype A Neurotoxin Light Chain Metalloprotease Reveals a Compact Binding Site Resulting from 60/70 Loop Flexibility.
Thompson, A.A., Jiao, G.S., Kim, S., Thai, A., Cregar-Hernandez, L., Margosiak, S.A., Johnson, A.T., Han, G.W., O'Malley, S., Stevens, R.C.(2011) Biochemistry 50: 4019-4028
- PubMed: 21434688
- DOI: https://doi.org/10.1021/bi2001483
- Primary Citation of Related Structures:
3QIX, 3QIY, 3QIZ, 3QJ0 - PubMed Abstract:
Neurotoxins synthesized by Clostridium botulinum bacteria (BoNT), the etiological agent of human botulism, are extremely toxic proteins making them high-risk agents for bioterrorism. Small molecule inhibitor development has been focused on the light chain zinc-dependent metalloprotease domain of the neurotoxin, an effort that has been hampered by its relatively flexible active site. Developed in concert with structure--activity relationship studies, the X-ray crystal structures of the complex of BoNT serotype A light chain (BoNT/A LC) with three different micromolar-potency hydroxamate-based inhibitors are reported here. Comparison with an unliganded BoNT/A LC structure reveals significant changes in the active site as a result of binding by the unique inhibitor scaffolds. The 60/70 loop at the opening of the active site pocket undergoes the largest conformational change, presumably through an induced-fit mechanism, resulting in the most compact catalytic pocket observed in all known BoNT/A LC structures.
Organizational Affiliation:
Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, United States.
