Ras-associating (RA) domain, FERM (Four.1 protein, Ezrin, Radixin, Moesin) domain, F0/F1 sub-domain, structurally similar to a beta-grasp ubiquitin-like fold
RA domain-containing proteins function by interacting, directly or indirectly, with Ras proteins and are involved in several different functions ranging from tumor suppression to being oncoproteins. Ras protein is a small GTPase that is involved in cellular signal transduction. The RA domain has the beta-grasp ubiquitin-like (Ubl) fold with low sequence similarity to ubiquitin (Ub). Ub is a protein modifier in eukaryotes that is involved in various cellular processes, including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes. RA-containing proteins include RalGDS, AF6, RIN, RASSF1, SNX27, CYR1, STE50, and phospholipase C epsilon. The FERM domain is present at the N-terminus of a large and diverse group of proteins that mediate linkage of the cytoskeleton to the plasma membrane. FERM-containing proteins are ubiquitous components of the cytocortex and are involved in cell transport, cell structure and signaling. The FERM domain is made up of three sub-domains, F1, F2, and F3. This family corresponds to the F1 sub-domain, also known as the N-terminal Ubl-like structural domain of the FERM domain (FERM_N), which is structurally similar to Ub. Some FERM domain-containing proteins contain an N-terminal region, which also has the beta-grasp Ub-like fold, precedes the FERM domain and has been referred to as the F0 domain.