Purification, crystallization, small-angle X-ray scattering and preliminary X-ray diffraction analysis of the SH2 domain of the Csk-homologous kinase.

ABSTRACT: The C-terminal Src kinase (Csk) and Csk-homologous kinase (CHK) are endogenous inhibitors of the proto-oncogenic Src family of protein tyrosine kinases (SFKs). Phosphotyrosyl peptide binding to their Src-homology 2 (SH2) domains activates Csk and CHK, enhancing their ability to suppress SFK signalling; however, the detailed mechanistic basis of this activation event is unclear. The CHK SH2 was expressed in Escherichia coli and the purified protein was characterized as monomeric by synchrotron small-angle X-ray scattering in-line with size-exclusion chromatography. The CHK SH2 crystallized in 0.2?M sodium bromide, 0.1?M bis-Tris propane pH 6.5 and 20% polyethylene glycol 3350 and the best crystals diffracted to ?1.6?Å resolution. The crystals belonged to space group P2, with unit-cell parameters a=25.8, b=34.6, c=63.2?Å, ?=99.4°.

SUBMITTER: Gunn NJ 

PROVIDER: S-EPMC3053158 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature