Expression, purification and preliminary X-ray diffraction studies of VERNALIZATION1(208-341) from Arabidopsis thaliana.

VERNALIZATION1 (VRN1) is required in the model plant Arabidopsis thaliana for the epigenetic suppression of the floral repressor FLC by prolonged cold treatment. Stable suppression of FLC accelerates flowering, a physiological process known as vernalization. VRN1 is a 341-residue DNA-binding protein that contains two plant-specific B3 domains (B3a and B3b), a putative nuclear localization sequence (NLS) and two putative PEST domains. VRN1(208-341) includes the second B3 domain and a region upstream that is highly conserved in the VRN1 orthologues of other dicotyledonous plants. VRN1(208-341) was crystallized by the hanging-drop method in 0.05 M sodium acetate pH 6.0 containing 1.0 M NaCl and 18%(w/v) PEG 3350. Preliminary X-ray diffraction data analysis revealed that the VRN1(208-341) crystal diffracted to 2.1 A and belonged to space group C2, with unit-cell parameters a = 105.2, b = 47.9, c = 61.2 A, alpha = 90.0, beta = 115.4, gamma = 90.0 degrees . Assuming that two molecules occupy the asymmetric unit, a Matthews coefficient of 2.05 A(3) Da(-1) and a solvent content of 40.1% were calculated.