3B61

EmrE multidrug transporter, apo crystal form

Summary for 3B61

• Entry DOI: 10.2210/pdb3b61/pdb
• Related: 3B5D 3B62
• Descriptor: Multidrug transporter emrE (1 entity in total)
• Functional Keywords: helical membrane protein, multidrug resistance transporter, smr, antiport, inner membrane, transmembrane, membrane protein
• Biological source: Escherichia coli K12
• Cellular location: Cell inner membrane; Multi-pass membrane protein: P23895
• Total number of polymer chains: 8
• Total formula weight: 95706.22

Authors

Chang, G.,Chen, Y.J. (deposition date: 2007-10-26, release date: 2007-12-04, Last modification date: 2024-02-21)

Primary citation

Chen, Y.J.,Pornillos, O.,Lieu, S.,Ma, C.,Chen, A.P.,Chang, G.
X-ray structure of EmrE supports dual topology model.
Proc.Natl.Acad.Sci.Usa, 104:18999-19004, 2007

PubMed Abstract: 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.

PubMed: 18024586
DOI: 10.1073/pnas.0709387104

Experimental method

X-RAY DIFFRACTION (4.5 Å)