Solution NMR evidence for symmetry in functionally or crystallographically asymmetric homodimers

J Am Chem Soc. 2011 Dec 14;133(49):19578-81. doi: 10.1021/ja206967d. Epub 2011 Nov 14.


A recurrent theme of many structural studies of homo-oligomeric protein systems is concerned with verification that the conformation observed in a crystal represents the functionally relevant structure. An asymmetric conformation adopted by two chemically identical subunits in homo-oligomers can represent an intrinsic property of a protein or be an artifact induced by crystal packing forces. Solution NMR studies can distinguish between these two possibilities. Using methyl-based NMR spectroscopy, we provide evidence for symmetry in the absence of ligands in several homodimeric proteins that are either asymmetric functionally and/or adopt different conformations of the two subunits in available X-ray structures.

MeSH terms

  • Bacterial Proteins / chemistry*
  • Crystallography, X-Ray
  • Cyclic AMP Receptor Protein / chemistry
  • Geobacillus stearothermophilus / chemistry*
  • Models, Molecular
  • Mycobacterium tuberculosis / chemistry*
  • Nuclear Magnetic Resonance, Biomolecular / methods*
  • Protein Conformation
  • Protein Multimerization


  • Bacterial Proteins
  • CRP protein, Mycobacterium tuberculosis
  • Cyclic AMP Receptor Protein