Crystallization and preliminary crystallographic analysis of a calcineurin B-like protein 1 (CBL1) mutant from Ammopiptanthus mongolicus.

Calcineurin B-like protein 1 (CBL1) is a calcium sensor in plants. It transmits the calcium signal through the downstream protein CBL-interacting protein kinase (CIPK). CBL1 and CIPK play crucial roles in the response to environmental stresses such as low K+, osmotic shock, high salt, cold and drought. Recombinant CBL1 from Ammopiptanthus mongolicus (AmCBL1) was overexpressed, purified and crystallized. However, the crystal did not diffract well. A mutant prepared using the surface-entropy method and crystallized using the hanging-drop method at 298 K with PEG 2000 MME as a precipitant diffracted to 2.90 Å resolution. The crystal belonged to space group P2(1)2(1)2, with unit-cell parameters a=99.87, b=114.42, c=63.80 Å, α=β=γ=90.00° and three molecules per asymmetric unit.