Structure of an SH2 domain of the p85 alpha subunit of phosphatidylinositol-3-OH kinase.
Booker, G.W., Breeze, A.L., Downing, A.K., Panayotou, G., Gout, I., Waterfield, M.D., Campbell, I.D.(1992) Nature 358: 684-687
- PubMed: 1323062 
- DOI: https://doi.org/10.1038/358684a0
- Primary Citation of Related Structures:  
2PNA, 2PNB - PubMed Abstract: 
Receptor protein-tyrosine kinases, through phosphorylation of specific tyrosine residues, generate high-affinity binding sites which direct assembly of multienzyme signalling complexes. Many of these signalling proteins, including phospholipase C gamma, GTPase-activating protein and phosphatidylinositol-3-OH kinase, contain src-homology 2 (SH2) domains, which bind with high affinity and specificity to tyrosine-phosphorylated sequences. The critical role played by SH2 domains in signalling has been highlighted by recent studies showing that mutation of specific phosphorylation sites on the platelet-derived growth factor receptor impair its association with phosphatidylinositol-3-OH kinase, preventing growth factor-induced mitogenesis. Here we report the solution structure of an isolated SH2 domain from the 85K regulatory subunit of phosphatidylinositol-3-OH kinase, determined using multidimensional nuclear magnetic resonance spectroscopy. The structure is characterized by a central region of beta-sheet flanked by two alpha-helices, with a highly flexible loop close to functionally important residues previously identified by site-directed mutagenesis.
Organizational Affiliation: 
Department of Biochemistry, University of Oxford, UK.