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From Proteopedia
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P-glycoprotein (Pgp) is an important human multidrug transporter that contributes to pharmacokinetics and multidrug resistance. Despite decades of study, the conformation transition cycle of Pgp undergoing active drug transport is not defined, thus the precise relevance of all available Pgp structures to uninterrupted multidrug transport remains unclear. Here, we use cryo-EM of membrane-embedded human Pgp under continuous turnover conditions to analyze the conformational ensembles of Pgp transporting distinct substrates. These results delineate multiple conformations including inward-facing and closed conformations, highlighting the occluded conformation as a critical intermediate state between transporter closure and substrate release. A combination of structural, functional, and computational studies reveals the transmembrane helices 4 and 10 undergoing drastic rearrangement to coordinate substrate binding, occlusion, and release, and identifies a peripheral site involved in substrate capture and Pgp inhibition. Together, our results provide a set of snapshots of Pgp undergoing continuous drug transport, unveiling the intricate interplay between transporter dynamics and drug movement, and shed light on the mechanism of polyspecificity. | P-glycoprotein (Pgp) is an important human multidrug transporter that contributes to pharmacokinetics and multidrug resistance. Despite decades of study, the conformation transition cycle of Pgp undergoing active drug transport is not defined, thus the precise relevance of all available Pgp structures to uninterrupted multidrug transport remains unclear. Here, we use cryo-EM of membrane-embedded human Pgp under continuous turnover conditions to analyze the conformational ensembles of Pgp transporting distinct substrates. These results delineate multiple conformations including inward-facing and closed conformations, highlighting the occluded conformation as a critical intermediate state between transporter closure and substrate release. A combination of structural, functional, and computational studies reveals the transmembrane helices 4 and 10 undergoing drastic rearrangement to coordinate substrate binding, occlusion, and release, and identifies a peripheral site involved in substrate capture and Pgp inhibition. Together, our results provide a set of snapshots of Pgp undergoing continuous drug transport, unveiling the intricate interplay between transporter dynamics and drug movement, and shed light on the mechanism of polyspecificity. | ||
| - | + | , PMID:40240353<ref>PMID:40240353</ref> | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
Current revision
CryoEM structure of P-Glycoprotein in inward facing 2 state under continuous turnover conditions with vinblastine
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