22102226 , Related PDB id: 3O5Z
- Chen S, Xiao Y, Ponnusamy R, Tan J, Lei J, Hilgenfeld R
- X-ray structure of the SH3 domain of the phosphoinositide 3-kinase p85beta subunit.
- Acta Crystallogr Sect F Struct Biol Cryst Commun. 2011 Nov 1;67(Pt 11):1328-33., Epub 2011 Oct 25.
- Src-homology 3 (SH3) domains are involved in extensive protein-protein interactions and constitute key elements of intracellular signal transduction. Three-dimensional structures have been reported for SH3 domains of various proteins, including the 85 kDa regulatory subunit (p85) of phosphoinositide 3-kinase. However, all of the latter structures are of p85 isoform alpha and no crystal structure of the SH3 domain of the equally important isoform beta has been reported to date. In this structural communication, the recombinant production, crystallization and X-ray structure determination at 2.0 A resolution of the SH3 domain of human p85beta is described. The structure reveals a compact beta-barrel fold very similar to that of p85alpha. However, binding studies with two classes of proline-rich ligand peptides demonstrate that the ligand-binding specificity differs slightly between the SH3 domains of human p85beta and p85alpha, despite their high structural similarity.