Download MendeleyCryo-EM Structures of CusA Reveal a Mechanism of Metal-Ion Export.
Moseng, M.A., Lyu, M., Pipatpolkai, T., Glaza, P., Emerson, C.C., Stewart, P.L., Stansfeld, P.J., Yu, E.W.(2021) mBio 12
- PubMed: 33820823
- DOI: https://doi.org/10.1128/mBio.00452-21
- Primary Citation of Related Structures:
7KF5, 7KF6, 7KF7, 7KF8 - 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 Escherichia coli 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. IMPORTANCE 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.
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
Organizational Affiliation:
