Crystal structures of the XLP protein SAP reveal a class of SH2 domains with extended, phosphotyrosine-independent sequence recognition.
Poy, F., Yaffe, M.B., Sayos, J., Saxena, K., Morra, M., Sumegi, J., Cantley, L.C., Terhorst, C., Eck, M.J.(1999) Mol Cell 4: 555-561
- PubMed: 10549287 
- DOI: 10.1016/s1097-2765(00)80206-3
- Primary Citation of Related Structures:  
1D1Z, 1D4W, 1D4T - PubMed Abstract: 
SAP, the product of the gene mutated in X-linked lymphoproliferative syndrome (XLP), consists of a single SH2 domain that has been shown to bind the cytoplasmic tail of the lymphocyte coreceptor SLAM. Here we describe structures that show that SAP binds phosphorylated and nonphosphorylated SLAM peptides in a similar mode, with the tyrosine or phosphotyrosine residue inserted into the phosphotyrosine-binding pocket ...