King Gordon, Hill Justine M, Martin Jennifer L, Mylne Joshua S
Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Mar 1;65(Pt 3):291-4. doi: 10.1107/S1744309109004217. Epub 2009 Feb 26.
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.
在模式植物拟南芥中，春化作用1（VRN1）是通过长时间的低温处理对开花抑制因子FLC进行表观遗传抑制所必需的。FLC的稳定抑制加速开花，这一生理过程被称为春化作用。VRN1是一种由341个氨基酸残基组成的DNA结合蛋白，包含两个植物特有的B3结构域（B3a和B3b）、一个假定的核定位序列（NLS）和两个假定的PEST结构域。VRN1（208 - 341）包括第二个B3结构域以及在其他双子叶植物的VRN1直系同源物中高度保守的上游区域。VRN1（208 - 341）通过悬滴法在含有1.0 M NaCl和18%（w/v）PEG 3350的0.05 M醋酸钠pH 6.0溶液中结晶。初步的X射线衍射数据分析表明，VRN1（208 - 341）晶体的衍射极限为2.1 Å，属于空间群C2，晶胞参数为a = 105.2，b = 47.9，c = 61.2 Å，α = 90.0，β = 115.4，γ = 90.0°。假设不对称单元中有两个分子，则计算出的马修斯系数为2.05 ų Da⁻¹，溶剂含量为40.1%。
