Krusell L, Rasmussen I, Gausing K
Department of Molecular and Structural Biology, University of Aarhus, Denmark.
FEBS Lett. 1997 May 12;408(1):25-9. doi: 10.1016/s0014-5793(97)00382-7.
The homeodomain of the knotted classes of transcription factors from plants differs from the well characterized Antp/En type homeodomains from Drosophila at key amino acid residues contributing to the DNA binding. A cDNA, Hvh21, derived from the hooded gene and encoding a full length homolog of knotted1 from maize was isolated from barley seedlings and expressed as a maltose binding protein fusion in E. coli. The purified HvH21-fusion protein selected DNA fragments with 1-3 copies of the sequence TGAC. Gel shift experiments showed that the TGAC element was required for binding and the results further indicate that the HvH21-fusion protein binds DNA as a monomer.
植物中结状转录因子类的同源异型结构域，在有助于DNA结合的关键氨基酸残基上，不同于果蝇中特征明确的Antp/En型同源异型结构域。从大麦幼苗中分离出一个源自hooded基因、编码玉米knotted1全长同源物的cDNA，即Hvh21，并在大肠杆菌中作为麦芽糖结合蛋白融合体表达。纯化的HvH21融合蛋白选择了含有1至3个TGAC序列拷贝的DNA片段。凝胶迁移实验表明，TGAC元件是结合所必需的，结果进一步表明HvH21融合蛋白以单体形式结合DNA。
