Solution structure of the Ras-binding domain of c-Raf-1 and identification of its Ras interaction surface

Biochemistry. 1995 May 30;34(21):6911-8. doi: 10.1021/bi00021a001.


The structure of the Ras-binding domain of human c-Raf-1 (residues 55-132) has been determined in solution by nuclear magnetic resonance (NMR) spectroscopy. Following complete assignment of the backbone and side-chain 1H, 15N, and 13C resonances, the structure was calculated using the program CHARMM. Over 1300 NOE-derived constraints were applied, resulting in a detailed structure. The fold of Raf55-132 consists of a five-stranded beta-sheet, a 12-residue alpha-helix, and an additional one-turn helix. It is similar to those of ubiquitin and the IgG-binding domain of protein G, although the three proteins share very little sequence identity. The surface of Raf55-132 that interacts with Ras has been identified by monitoring perturbation of line widths and chemical shifts of 15N-labeled Raf55-132 resonances during titration with unlabeled Ras-GMPPNP. The Ras-binding site is contained within a spatially contiguous patch comprised of the N-terminal beta-hairpin and the C-terminal end of the alpha-helix.

MeSH terms

  • Binding Sites
  • Humans
  • Magnetic Resonance Spectroscopy
  • Protein Conformation
  • Protein-Serine-Threonine Kinases / chemistry
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / chemistry
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-raf
  • Solutions
  • ras Proteins / metabolism*


  • Proto-Oncogene Proteins
  • Solutions
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-raf
  • ras Proteins