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Title | Cryo-EM Structures of CusA Reveal a Mechanism of Metal-Ion Export. |
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Journal, issue, pages | mBio, Vol. 12, Issue 2, Year 2021 |
Publish date | Apr 5, 2021 |
Authors | Mitchell A Moseng / Meinan Lyu / Tanadet Pipatpolkai / Przemyslaw Glaza / Corey C Emerson / Phoebe L Stewart / Phillip J Stansfeld / Edward W Yu / |
PubMed Abstract | Gram-negative bacteria utilize the resistance-nodulation-cell division (RND) superfamily of efflux pumps to expel a variety of toxic compounds from the cell. The CusA membrane protein, which ...Gram-negative bacteria utilize the resistance-nodulation-cell division (RND) superfamily of efflux pumps to expel a variety of toxic compounds from the cell. The CusA membrane protein, which recognizes and extrudes biocidal Cu(I) and Ag(I) ions, belongs to the heavy-metal efflux (HME) subfamily of RND efflux pumps. We here report four structures of the trimeric CusA heavy-metal efflux pump in the presence of Cu(I) using single-particle cryo-electron microscopy (cryo-EM). We discover that different CusA protomers within the trimer are able to bind Cu(I) ions simultaneously. Our structural data combined with molecular dynamics (MD) simulations allow us to propose a mechanism for ion transport where each CusA protomer functions independently within the trimer. The bacterial RND superfamily of efflux pumps mediate resistance to a variety of biocides, including Cu(I) and Ag(I) ions. Here we report four cryo-EM structures of the trimeric CusA pump in the presence of Cu(I). Combined with MD simulations, our data indicate that each CusA protomer within the trimer recognizes and extrudes Cu(I) independently. |
External links | mBio / PubMed:33820823 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.8 - 3.4 Å |
Structure data | EMDB-22843, PDB-7kf5: EMDB-22844, PDB-7kf6: EMDB-22845, PDB-7kf7: EMDB-22846, PDB-7kf8: |
Chemicals | ChemComp-CU1: |
Source |
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Keywords | MEMBRANE PROTEIN / TRANSPORT PROTEIN / efflux / pump / heavy metal. copper / silver / closed / open / transport / MEMBRANE PROTEIN/ TRANSPORT PROTEIN / transporter / MEMBRANE PROTEIN- TRANSPORT PROTEIN complex |