X-ray structure of the SH3 domain of the phosphoinositide 3-kinase p85? subunit.

ABSTRACT: 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 ? and no crystal structure of the SH3 domain of the equally important isoform ? has been reported to date. In this structural communication, the recombinant production, crystallization and X-ray structure determination at 2.0 Å resolution of the SH3 domain of human p85? is described. The structure reveals a compact ?-barrel fold very similar to that of p85?. 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 p85? and p85?, despite their high structural similarity.

SUBMITTER: Chen S 

PROVIDER: S-EPMC3212445 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature