| Primary Identifier | IPR036537 | Type | Homologous_superfamily |
| Short Name | Adaptor_Cbl_N_dom_sf |
| description | Cbl (Casitas B-lineage lymphoma) is an adaptor protein that functions as a negative regulator of many signalling pathways that start from receptors at the cell surface.The N-terminal region of Cbl contains a Cbl-type phosphotyrosine-binding (Cbl-PTB) domain, which is composed of three evolutionarily conserved domains: an N-terminal four-helix bundle (4H) domain, an EF hand-like calcium-binding domain, and a divergent SH2-like domain. The calcium-bound EF-hand wedges between the 4H and SH2 domains, and roughly determines their relative orientation. The Cbl-PTB domain has also been named Cbl N-terminal (Cbl-N) or tyrosine kinase binding (TKB) domain [, ].The N-terminal 4H domain contains four long α-helices. The C and D helices in this domain pack against the adjacent EF-hand-like domain, and a highly conserved loop connecting the A and B helices contacts the SH2-like domain. The EF-hand motif is similar to classical EF-hand proteins. The SH2-likedomain retains the general helix-sheet-helix architecture of the SH2 fold, but lacks the secondary β-sheet, comprising β-strands D', E and F, and also a prominent BG loop [].This entry represents the N-terminal four-helical bundle domain superfamily. This domain can also be found in the N terminus of mammalian MLKL, a pseudokinase essential for TNF-alpha-induced necroptosis []. The four-helical bundle (NB) domain of MLK is involved in oligomerization to facilitate plasma membrane targeting through the low-affinity binding of NB to phosphorylated inositol polar head groups of phosphatidylinositol phosphate (PIP) phospholipids [, ]. |
