The Src homology 2 (SH2) domain is a protein domain of about 100 amino-acid
residues first identified as a conserved sequence region between the
oncoproteins Src and Fps . Similar sequences were later found in many other
intracellular signal-transducing proteins . SH2 domains function as
regulatory modules of intracellular signalling cascades by interacting with
high affinity to phosphotyrosine-containing target peptides in a sequence-specific and strictly phosphorylation-dependent manner [3,4,5,6].
The SH2 domain has a conserved 3D structure consisting of two α helices
and six to seven β-strands. The core of the domain is formed by a
continuous β-meander composed of two connected β-sheets .
So far, SH2 domains have been identified in the following proteins:
Many vertebrate, invertebrate and retroviral cytoplasmic (non-receptor)
protein tyrosine kinases. In particular in the Src, Abl, Bkt, Csk and ZAP70
families of kinases.
Mammalian phosphatidylinositol-specific phospholipase C γ-1 and -2. Two
copies of the SH2 domain are found in those proteins in between the
catalytic 'X-' and 'Y-boxes' (see <PDOC50007>).
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