7ZK8

ABCB1 L971C mutant (mABCB1) in the outward facing state bound to AAC

Summary for 7ZK8

• Entry DOI: 10.2210/pdb7zk8/pdb
• EMDB information: 14758
• Descriptor: ATP-dependent translocase ABCB1, ADENOSINE-5'-TRIPHOSPHATE, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: abc transporter, membrane protein
• Biological source: Mus musculus (house mouse)
• Total number of polymer chains: 1
• Total formula weight: 142729.98

Authors

Parey, K.,Januliene, D.,Gewering, T.,Moeller, A. (deposition date: 2022-04-12, release date: 2023-04-26, Last modification date: 2024-11-13)

Primary citation

Gewering, T.,Waghray, D.,Parey, K.,Jung, H.,Tran, N.N.B.,Zapata, J.,Zhao, P.,Chen, H.,Januliene, D.,Hummer, G.,Urbatsch, I.,Moeller, A.,Zhang, Q.
Tracing the substrate translocation mechanism in P-glycoprotein.
Elife, 12:-, 2024

PubMed Abstract: P-glycoprotein (Pgp) is a prototypical ATP-binding cassette (ABC) transporter of great biological and clinical significance.Pgp confers cancer multidrug resistance and mediates the bioavailability and pharmacokinetics of many drugs (Juliano and Ling, 1976; Ueda et al., 1986; Sharom, 2011). Decades of structural and biochemical studies have provided insights into how Pgp binds diverse compounds (Loo and Clarke, 2000; Loo et al., 2009; Aller et al., 2009; Alam et al., 2019; Nosol et al., 2020; Chufan et al., 2015), but how they are translocated through the membrane has remained elusive. Here, we covalently attached a cyclic substrate to discrete sites of Pgp and determined multiple complex structures in inward- and outward-facing states by cryoEM. In conjunction with molecular dynamics simulations, our structures trace the substrate passage across the membrane and identify conformational changes in transmembrane helix 1 (TM1) as regulators of substrate transport. In mid-transport conformations, TM1 breaks at glycine 72. Mutation of this residue significantly impairs drug transport of Pgp in vivo, corroborating the importance of its regulatory role. Importantly, our data suggest that the cyclic substrate can exit Pgp without the requirement of a wide-open outward-facing conformation, diverting from the common efflux model for Pgp and other ABC exporters. The substrate transport mechanism of Pgp revealed here pinpoints critical targets for future drug discovery studies of this medically relevant system.

PubMed: 38259172
DOI: 10.7554/eLife.90174

Experimental method

ELECTRON MICROSCOPY (3 Å)