Structure of outer membrane protein G by solution NMR spectroscopy
- Department of Molecular Physiology and Biological Physics, University of Virginia, 1300 Jefferson Park Avenue, P.O. Box 800736, Charlottesville, VA 22908
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Edited by Adriaan Bax, National Institutes of Health, Bethesda, MD, and approved August 15, 2007 (received for review June 11, 2007)
Abstract
The bacterial outer membrane protein G (OmpG), a monomeric pH-gated porin, was overexpressed in Escherichia coli and refolded in β-octyl glucoside micelles. After transfer into dodecylphosphocholine micelles, the solution structure of OmpG was determined by solution NMR spectroscopy at pH 6.3. Complete backbone assignments were obtained for 234 of 280 residues based on CA, CB, and CO connection pathways determined from a series of TROSY-based 3D experiments at 800 MHz. The global fold of the 14-stranded β-barrel was determined based on 133 long-range NOEs observed between neighboring strands and local chemical shift and NOE information. The structure of the barrel is very similar to previous crystal structures, but the loops of the solution structure are quite flexible.
Footnotes
- *To whom correspondence should be addressed. E-mail: lkt2e{at}virginia.edu
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Author contributions: B.L. and L.K.T. designed research; B.L. performed research; B.L. and L.K.T. analyzed data; and B.L. and L.K.T. wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS Direct Submission.
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Data deposition: The coordinates of the OmpG structure have been deposited in the Protein Data Bank, www.pdb.org (PDB ID code 2JQY).
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This article contains supporting information online at www.pnas.org/cgi/content/full/0705466104/DC1.
- Abbreviations:
- DPC,
- dodecylphosphocholine;
- MP,
- membrane protein.
- © 2007 by The National Academy of Sciences of the USA
