In Vivo Trp Scanning of the Small Multidrug Resistance Protein EmrE Confirms 3D Structure Models'

JOURNAL OF MOLECULAR BIOLOGY

卷:425

Article

Lloris-Garcera, Pilar¹  Slusky, Joanna S. G.¹  Seppala, Susanna^1,2  Priess, Marten²  Schaefer, Lars V.²  von Heijne, Gunnar^1,3 

[1] Stockholm Univ, Dept Biochem & Biophys, Ctr Biomembrane Res, SE-10691 Stockholm, Sweden

[2] Goethe Univ Frankfurt, Inst Phys & Theoret Chem, D-60438 Frankfurt, Germany

[3] Stockholm Univ, Sci Life Lab, SE-17177 Solna, Sweden

关键词: EmrE;    multidrug resistance;    Trp scan;   

DOI  :  10.1016/j.jmb.2013.07.039

来源: Elsevier

【 摘 要 】

The quaternary structure of the homodimeric small multidrug resistance protein EmrE has been studied intensely over the past decade. Structural models derived from both two- and three-dimensional crystals show EmrE as an anti-parallel homodinner. However, the resolution of the structures is rather low and their relevance for the in vivo situation has been questioned. Here, we have challenged the available structural models by a comprehensive in vivo Trp scanning of all four transmembrane helices in EmrE. The results are in close agreement with the degree of lipid exposure of individual residues predicted from coarse-grained molecular dynamics simulations of the anti-parallel dimeric structure obtained by X-ray crystallography, strongly suggesting that the X-ray structure provides a good representation of the active in vivo form of EmrE (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free