Journal of Protein Chemistry

, Volume 14, Issue 8, pp 721–730

Structural effects of the binding of GTP to the wild-type and oncogenic forms of theras-gene-encoded p21 proteins

Authors

  • Regina Monaco
    • Department of ChemistryNew York University
    • Department of Pathology and Laboratory MedicineVeterans Affairs Medical Center
    • Department of PathologySUNY Health Science Center at Brooklyn
  • James M. Chen
    • Dupont Agricultural ProductsStein-Haskell Research Center
  • Fred K. Friedman
    • Laboratory of Molecular CarcinogenesisNational Institutes of Health
  • Paul Brandt-Rauf
    • Division of Environmental SciencesColumbia College of Physicians and Surgeons
  • Denise Chung
    • Department of ChemistryLong Island University
  • Matthew R. Pincus
    • Department of Pathology and Laboratory MedicineVeterans Affairs Medical Center
    • Department of PathologySUNY Health Science Center at Brooklyn
Article

DOI: 10.1007/BF01886911

Cite this article as:
Monaco, R., Chen, J.M., Friedman, F.K. et al. J Protein Chem (1995) 14: 721. doi:10.1007/BF01886911
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Abstract

Molecular dynamics calculations have been performed to determine the average structures ofras-gene-encoded p21 proteins bound to GTP, i.e., the normal (wild-type) protein and two oncogenic forms of this protein, the Val 12- and Leu 61-p21 proteins. We find that the average structures for all of these proteins exhibit low coordinate fluctuations (which are highest for the normal protein), indicating convergence to specific structures. From previous dynamics calculations of the average structures of these proteins bound to GDP, major regional differences were found among these proteins (Monacoet al. (1995),J. Protein Chem., in press). We now find that the average structures of the oncogenic proteins are more similar to one another when the proteins are bound to GTP than when they are bound to GDP (Monacoet al. (1995),J. Protein Chem., in press). However, they still differ in structureat specific amino acid residues rather than in whole regions, in contradistinction to the results found for the p21-GDP complexes. Two exceptions are the regions 25–32, in anα-helical region, and 97–110. The two oncogenic (Val 12- and Leu 61-) proteins have similar structures which differ significantly in the region of residues 97–110. This region has recently been identified as being critical in the interaction of p21 with kinase target proteins. The differences in structure between the oncogenic proteins suggest the existence of more than one oncogenic form of the p21 protein that can activate different signaling pathways.

Key words

Oncogenic p21 proteinsmolecular dynamicsGTPchanges in conformationeffector domains

Copyright information

© Plenum Publishing Corporation 1995