PROSITE documentation PDOC51506
Cbl-type phosphotyrosine-binding (Cbl-PTB) domain profile


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 evolutionarily conserved amino-terminal region of Cbl (Cbl-N) binds to phosphorylated tyrosine residues and has cell-transforming activity. The N-terminal Cbl-type phosphotyrosine-binding (Cbl-PTB) domain is composed of three interacting domains: a four-helix bundle (4H), an EF-hand-like calcium-binding domain (see <PDOC00018>), and a divergent SH2-like domain (see <PDOC50001>). The calcium-bound EF-hand wedges between the 4H and SH2 domains, and roughly determines their relative orientation. The three domains together form an integrated phosphoprotein-recognition module. The Cbl-PTB has also been named Cbl N-terminal (Cbl-N) or tyrosine kinase binding (TKB) domain [1,2].

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-like domain in Cbl-N 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 (see <PDB:2CBL>) [1].

The profile we developed covers the entire Cbl-PTB domain.

Last update:

August 2010 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

CBL_PTB, PS51506; Cbl-type phosphotyrosine-binding (Cbl-PTB) domain profile  (MATRIX)


1AuthorsMeng W. Sawasdikosol S. Burakoff S.J. Eck M.J.
TitleStructure of the amino-terminal domain of Cbl complexed to its binding site on ZAP-70 kinase.
SourceNature 398:84-90(1999).
PubMed ID10078535

2AuthorsLangenick J. Araki T. Yamada Y. Williams J.G.
TitleA Dictyostelium homologue of the metazoan Cbl proteins regulates STAT signalling.
SourceJ. Cell. Sci. 121:3524-3530(2008).
PubMed ID18840649

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