Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the LRR domain of the LePRK1 receptor-like kinase from tomato.

LePRK1 is a receptor-like kinase involved in successful fertilization in Lycopersicon esculentum (tomato). Importantly, the extracellular leucine-rich repeat (LRR) domain of LePRK1 mediates transmembrane signal transduction for pollen-tube growth and pollen germination. In this study, the N-terminal extracellular LRR domain of L. esculentum-derived LePRK1 was purified using an insect-cell secretion expression system and was crystallized by the vapour-diffusion method. The crystals diffracted X-rays to a resolution of 2.75 Å using synchrotron radiation. The crystals belonged to space group C2, with unit-cell parameters a = 136.53, b = 56.01, c = 62.93 Å, β = 108.99° and two molecules per asymmetric unit.