Download MendeleyFunctional implications of the conformational landscape of a multidrug transporter revealed by Zebrafish Abcb4 structures.
Zhan, J., Hsieh, C.M., Esser, L., Lang, Z.C., Morton, A.J., Robey, R., Zhou, F., Ambudkar, S.V., Huang, R.K., Gottesman, M.M., Xia, D.(2026) Nat Commun
- PubMed: 42218127 Search on PubMed
- DOI: https://doi.org/10.1038/s41467-026-73751-4
- Primary Citation Related Structures:
9ODY, 9ODZ, 9OE0, 9OE1, 9OE2, 9OE4, 9OE5, 9OE6, 9OE7, 9OE8, 9OE9 - PubMed Abstract:
The hallmark of multidrug resistance conferred by the human ABC transporter ABCB1 (hP-gp) is the recognition and efflux of a diverse range of drugs, though the precise mechanism of polyspecificity remains unresolved. In aquatic animals such as zebrafish, Abcb4, a functional homolog of hP-gp, plays a vital role in surviving environmental toxicants. Here, we show that DrAbcb4 exhibits comparable basal and drug-stimulated ATPase activity to hP-gp. Using cryo-EM, we capture five inward-facing DrAbcb4 conformations with varying separations between its two lobes, illustrating its open-and-close motion. The range of separation exceeds that seen in published P-gp structures that appear to be conformationally restricted. This global open-and-close motion is coupled with individual helix movement, resulting in a highly fluid substrate-binding pocket. These dynamic changes, likely underlying the polyspecificity of substrate recognition, predict unconventional protein-ligand interactions that are supported by structures of DrAbcb4 bound to the P-gp inhibitors tariquidar and elacridar, and the substrate vincristine.
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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