Crystal structure of the breakpoint cluster region-homology domain from phosphoinositide 3-kinase p85α subunit Article Conference Paper uri icon


MeSH Major

  • Medical Oncology


  • Proteins such as the product of the break-point cluster region, chimaerin, and the Src homology 3-binding protein 3BP1, are GTPase activating proteins (GAPs) for members of the Rho subfamily of small GTP-binding proteins (G proteins or GTPases). A 200-residue region, named the breakpoint cluster region-homology (BH) domain, is responsible for the GAP activity. We describe here the crystal structure of the BH domain from the p85 subunit of phosphatidylinositol 3-kinase at 2.0 A resolution. The domain is composed of seven helices, having a previously unobserved arrangement. A core of four helices contains most residues that are conserved in the BH family. Their packing suggests the location of a G-protein binding site. This structure of a GAP-like domain for small GTP-binding proteins provides a framework for analyzing the function of this class of molecules.

publication date

  • December 10, 1996



  • Conference Paper


Digital Object Identifier (DOI)

  • 10.1073/pnas.93.25.14373

PubMed ID

  • 8962058

Additional Document Info

start page

  • 14373

end page

  • 8


  • 93


  • 25