Crystal structure of the Bruton's tyrosine kinase PH domain with phosphatidylinositol
Murayama, K., Kato-Murayama, M., Mishima, C., Akasaka, R., Shirouzu, M., Fukui, Y., Yokoyama, S.(2008) Biochem Biophys Res Commun 377: 23-28
- PubMed: 18809383 
- DOI: https://doi.org/10.1016/j.bbrc.2008.09.055
- Primary Citation of Related Structures:  
2Z0P - PubMed Abstract: 
Bruton's tyrosine kinase (Btk) of the Tec family possesses a Pleckstrin homology (PH) domain, which is responsible for plasma membrane targeting. In this study, the crystal structure of the Btk PH domain in complex with dibutylyl-phosphatidylinositol-3,4,5-triphosphate was determined. The structure revealed that the Btk PH domain forms a homodimer and that each molecule binds phosphatidylinositol in the binding pocket. The side chain of Lys18 within a Btk-specific insertion in the beta1-beta2 loop is able to form a hydrogen bond with the diacylglycerol moiety of phosphatidylinositol. The other Btk-specific insertion in the beta5-beta6 loop constitutes the dimerization interface. Thus, the modes of phosphatidylinositol recognition and Btk PH domain dimerization are distinct from those of other PH domains.
Organizational Affiliation: 
Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan.