Crystallization and preliminary X-ray crystallographic analysis of the human CKIP-1 pleckstrin homology domain.

The casein kinase 2 interacting protein-1 (CKIP-1) is involved in many cellular functions, including apoptosis, signalling pathways, cell growth, cytoskeleton and bone formation. Its N-terminal pleckstrin homology (PH) domain is thought to play an important role in membrane localization and controls shuttling of CKIP-1 between the plasma membrane and nucleus. In this study, the human CKIP-1 PH domain was purified but problems were encountered with nucleic acid contamination. An S84D/S86D/S88D triple mutant designed to abolish nucleic acid binding was purified and successfully crystallized. Single crystals diffracted to 1.7 Å resolution and belonged to space group P4₃2₁2 with unit-cell parameters a=53.0, b=53.0, c=113.8 Å, α=β=γ=90.0°.