You can manage bookmarks using lists, please log in to your user account for this.
Media type:
E-Article
Title:
X-ray Structure of the EmrE Multidrug Transporter in Complex with a Substrate
Contributor:
Pornillos, Owen;
Chen, Yen-Ju;
Chen, Andy P.;
Chang, Geoffrey
Published:
American Association for the Advancement of Science (AAAS), 2005
Published in:
Science, 310 (2005) 5756, Seite 1950-1953
Language:
English
DOI:
10.1126/science.1119776
ISSN:
0036-8075;
1095-9203
Origination:
Footnote:
Description:
EmrE is a prototype of the Small Multidrug Resistance family of efflux transporters and actively expels positively charged hydrophobic drugs across the inner membrane of Escherichia coli . Here, we report the x-ray crystal structure, at 3.7 angstrom resolution, of one conformational state of the EmrE transporter in complex with a translocation substrate, tetraphenylphosphonium. Two EmrE polypeptides form a homodimeric transporter that binds substrate at the dimerization interface. The two subunits have opposite orientations in the membrane and adopt slightly different folds, forming an asymmetric antiparallel dimer. This unusual architecture likely confers unidirectionality to transport by creating an asymmetric substrate translocation pathway. On the basis of available structural data, we propose a model for the proton-dependent drug efflux mechanism of EmrE.