3B5D image
Entry Detail
PDB ID:
3B5D
Title:
EmrE multidrug transporter in complex with TPP, C2 crystal form
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2007-10-25
Release Date:
2007-12-04
Method Details:
Experimental Method:
Resolution:
3.80 Å
R-Value Free:
0.36
R-Value Work:
0.32
Space Group:
C 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Multidrug transporter emrE
Chain IDs:A, B
Chain Length:110
Number of Molecules:2
Biological Source:Escherichia coli K12
Ligand Molecules
Primary Citation
X-ray structure of EmrE supports dual topology model.
Proc.Natl.Acad.Sci.Usa 104 18999 19004 (2007)
PMID: 18024586 DOI: 10.1073/pnas.0709387104

Abstact

EmrE, a multidrug transporter from Escherichia coli, functions as a homodimer of a small four-transmembrane protein. The membrane insertion topology of the two monomers is controversial. Although the EmrE protein was reported to have a unique orientation in the membrane, models based on electron microscopy and now defunct x-ray structures, as well as recent biochemical studies, posit an antiparallel dimer. We have now reanalyzed our x-ray data on EmrE. The corrected structures in complex with a transport substrate are highly similar to the electron microscopy structure. The first three transmembrane helices from each monomer surround the substrate binding chamber, whereas the fourth helices participate only in dimer formation. Selenomethionine markers clearly indicate an antiparallel orientation for the monomers, supporting a "dual topology" model.

Legend

Protein

Chemical

Disease

Primary Citation of related structures