New insights into the structure and oligomeric state of the bacterial multidrug transporter EmrE: an unusual asymmetric homo‐dimer

FEBS Letters

Tate, C.G¹  Ubarretxena-Belandia, I¹ 

[1] MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK

关键词: Asymmetry;    Electron crystallography;    Membrane protein;    Multidrug;    Structure;   

DOI  :  10.1016/S0014-5793(04)00228-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

EmrE is a small multidrug transporter that contains 110 amino acid residues that form four transmembrane α-helices. The three-dimensional structure of EmrE has been determined from two-dimensional crystals by electron cryo-microscopy. EmrE is an asymmetric homo-dimer with one substrate molecule bound in a chamber accessible laterally from one leaflet of the lipid bilayer. Evidence from substrate binding analyses and analytical ultracentrifugation of detergent-solubilised EmrE shows that the minimum functional unit for substrate binding is a dimer. However, it is possible that EmrE exists as a tetramer in vivo and plausible models are suggested based upon analyses of two-dimensional crystals.

【 授权许可】

Unknown