8ZAR
EmrAB-TolC MFS-type tripartite multidrug efflux pump FA
This is a non-PDB format compatible entry.
Summary for 8ZAR
| Entry DOI | 10.2210/pdb8zar/pdb |
| EMDB information | 39885 |
| Descriptor | Multidrug export protein EmrA, Multidrug export protein EmrB, Outer membrane protein TolC (3 entities in total) |
| Functional Keywords | multidrug efflux pump, mfs, emrab, structural protein |
| Biological source | Escherichia coli K-12 More |
| Total number of polymer chains | 10 |
| Total formula weight | 495587.23 |
| Authors | Du, D.,Zhong, Z.,Tuerxunjiang, M. (deposition date: 2024-04-25, release date: 2025-04-30, Last modification date: 2026-05-13) |
| Primary citation | Zhong, Z.,Maimaiti, T.,Jackson, M.L.,Dong, R.,Gao, X.,Ouyang, Q.,Wang, W.,Guo, J.,Li, S.,Shang, W.,Liu, H.,Jiang, H.,Zhang, S.,Zachariae, U.,Luisi, B.F.,Chao, Y.,Du, D. A model for drug transport across two membranes of Gram-negative bacteria by an MFS tripartite assembly. Nat Commun, 17:-, 2026 Cited by PubMed Abstract: Transport of proteins and small molecules across cellular membrane is crucial for bacterial interaction with the environment and survival against antibiotics. In Gram-negative bacteria that possess two layers of membranes, specialized macromolecular machines are required to transport substrates across the cell envelope, often via an indirect stepwise process. The major facilitator superfamily (MFS)-type tripartite efflux pumps use proton electrochemical gradient to extrude drugs in diverse bacterial species, but the architecture of the assembly and structural mechanisms remain elusive. A representative MFS-type tripartite efflux pump, EmrAB-TolC, mediates resistance to multiple antimicrobial drugs through proton-coupled EmrB, a member of the DHA2 transporter family. Here, we report the high-resolution (3.13 Å) structure of the EmrAB-TolC pump, revealing a distinct, asymmetric architecture emerging from the assembly of TolC:EmrA:EmrB with a ratio of 3:6:1 and contacts that are essential for the pump assembly. Key residues involved in drug transport are identified and corroborated by mutagenesis and antibiotic sensitivity assays. The structural and functional data support a model for one-step drug transport by the MFS pump across the entire envelope of Gram-negative bacteria. PubMed: 41839863DOI: 10.1038/s41467-026-70500-5 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.59 Å) |
Structure validation
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