sentences:  The PDB file 1H3H depicts the SH3 domain of GRAP2 in complex with an RSTK-containing peptide representing residues 226–235 of SLP-76.SLP-76 was originally identified as a substrate of the ZAP-70 protein tyrosine kinase following T cell receptor (TCR) ligation in the leukemic T cell line Jurkat.The SLP-76 locus has been localized to human chromosome 5q33 and the gene structure has been partially characterized in mice.