Snapshots of ligand entry, malleable binding and induced helical movement in P-glycoprotein.Szewczyk, P., Tao, H., McGrath, A.P., Villaluz, M., Rees, S.D., Lee, S.C., Doshi, R., Urbatsch, I.L., Zhang, Q., Chang, G.
(2015) Acta Crystallogr D Biol Crystallogr 71: 732-741
- PubMed: 25760620
- DOI: https://doi.org/10.1107/S1399004715000978
- Primary Citation of Related Structures:
4Q9H, 4Q9I, 4Q9J, 4Q9K, 4Q9L
- PubMed Abstract:
P-glycoprotein (P-gp) is a transporter of great clinical and pharmacological significance. Several structural studies of P-gp and its homologs have provided insights into its transport cycle, but questions remain regarding how P-gp recognizes diverse substrates and how substrate binding is coupled to ATP hydrolysis. Here, four new P-gp co-crystal structures with a series of rationally designed ligands are presented. It is observed that the binding of certain ligands, including an ATP-hydrolysis stimulator, produces a large conformational change in the fourth transmembrane helix, which is positioned to potentially transmit a signal to the nucleotide-binding domains. A new ligand-binding site on the surface of P-gp facing the inner leaflet of the membrane is also described, providing vital insights regarding the entry mechanism of hydrophobic drugs and lipids into P-gp. These results represent significant advances in the understanding of how P-gp and related transporters bind and export a plethora of metabolites, antibiotics and clinically approved and pipeline drugs.
Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92023, USA.