Download MendeleyStructural mechanisms of pump assembly and drug transport in the AcrAB-TolC efflux system.
Ge, X., Gu, Z., Wang, J.(2026) Elife 14
- PubMed: 42007677 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.7554/eLife.109684
- Primary Citation Related Structures:
9V52, 9V53, 9V55 - PubMed Abstract:
Tripartite multidrug efflux pumps that span the cell envelope are essential for antibiotic resistance in Gram-negative bacteria. Here, we report cryo-EM structures of two endogenous efflux complexes from Escherichia coli : a TolC-YbjP subcomplex at 3.56 Å resolution and the complete TolC-YbjP-AcrABZ pump at 3.39 Å. Structural analysis reveals that YbjP, a previously uncharacterized lipoprotein, binds TolC in a 3:3 stoichiometry, bridging the TolC protomers at their equatorial domain. Clear density of the mature YbjP's N-terminal Cys19 indicates that YbjP is anchored to the outer membrane by an N-terminal lipid moiety. Notably, YbjP remains bound as TolC undergoes AcrA-induced opening, suggesting that this accessory protein accommodates the conformational change. The AcrB trimer simultaneously presents three distinct conformational states (L, T, and O), capturing a complete transport cycle. These high-resolution structures provide insights into the architecture and mechanism of clinically relevant efflux machinery, identifying YbjP as a previously unrecognized structural component that contributes to TolC positioning, and may assist in its membrane localization.
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China.
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