Download MendeleySeparate Entrance and Exit Portals for Ligand Traffic in Mycobacterium tuberculosis FabH
Sachdeva, S., Musayev, F.N., Alhamadsheh, M.M., Scarsdale, J.N., Wright, H.T., Reynolds, K.A.(2008) Chem Biol 15: 402-412
- PubMed: 18420147
- DOI: https://doi.org/10.1016/j.chembiol.2008.03.007
- Primary Citation of Related Structures:
2QNX, 2QNY, 2QNZ, 2QO0, 2QO1 - PubMed Abstract:
Mycobacterium tuberculosis FabH initiates type II fatty acid synthase-catalyzed formation of the long chain (C(16)-C(22)) acyl-coenzyme A (CoA) precursors of mycolic acids, which are major constituents of the bacterial cell envelope. Crystal structures of M. tuberculosis FabH (mtFabH) show the substrate binding site to be a buried, extended L-shaped channel with only a single solvent access portal. Entrance of an acyl-CoA substrate through the solvent portal would require energetically unfavorable reptational threading of the substrate to its reactive position. Using a class of FabH inhibitors, we have tested an alternative hypothesis that FabH exists in an "open" form during substrate binding and product release, and a "closed" form in which catalysis and intermediate steps occur. This hypothesis is supported by mass spectrometric analysis of the product profile and crystal structures of complexes of mtFabH with these inhibitors.
- Department of Chemistry, Portland State University, Portland, OR 97207, USA.
Organizational Affiliation:
