Tertiary contacts, sequence-structure-function

The biologic function of Ras is mediated by its ability to activate downstream cytoplasmic signaling networks through binding to a panel of effector proteins. The Ras-effector interaction is mediated through interactions between the core effector domain (amino acids 32 0) of Ras (see Fig. 2) and the specific residues within the Ras-binding domain (RBD) or Ras-association domain (RA) found in most Ras effector proteins. The RBDs and RA domains of effector proteins do not exhibit primary sequence homology, but instead they share a common tertiary structure that consists of an ubiquitin superfold, which forms critical contacts with Ras (33). 

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