绒毛白蜡smh1基因编码区的克隆及序列分析

Cloning and Sequence Analysis of Fraxinus velutina smh1 Gene Coding Region

为探究绒毛白蜡smh1端粒结合蛋白基因在端粒中的作用以及在植物生长发育过程中的调控机制,进行绒毛白蜡smh1端粒结合蛋白基因克隆及分析。以绒毛白蜡幼苗为试材,Illumina Hi Seq 2000高通量测序技术获得的绒毛白蜡转录组Unigene数据为基础,采用RT-PCR方法克隆绒毛白蜡smh1基因编码区序列并进行生物信息学分析。结果表明:从绒毛白蜡叶片中成功克隆出一个smh类端粒结合蛋白基因编码区序列。基因编码区长度为879 bp,可编码292个氨基酸,分子量为31.66 k Da,等电点为6.5,原子总数为4457个,分子式为C_(1371)H_(2242)N_(392)O_(439)S_(13)。Conserved Domains数据库对蛋白质的保守结构域进行分析,结果显示该蛋白序列具有植物端粒结合蛋白Smh(single myb histone)亚家族典型的结构特征,包括位于N-端的Myb样结构域以及中间的组蛋白H1/5样结构域。将Fv Smh1端粒结合蛋白与含有telobox基序的其他端粒结合蛋白进行系统进化树的构建,结果显示SMH端粒结合蛋白与TRF1和TRF2同属一个分支,具有较近的关系。从上述分析结果可以推断所克隆的绒毛白蜡smh1基因可能对植物端粒结构的维持和功能的发挥具有重要作用。

To study the function of Fraxinus velutina smhl telomere binding protein gene in telomere and its regulation mechanism in the process of plant growth and development, we cloned and analyzed Fraxinus velutina smhl telomere binding protein gene. By selecting Fraxinus velutina seedling as experiment material and based on the transcriptome Unigene data which gained by Illumina HiSeq 2000 high throughput sequencing technology, we chose RT-PCR method to clone Fraxinus velutina smhl gene coding region, and then conducted bioinformatics analysis. The results showed that a sequence of Fraxinus velutina smh gene coding region was cloned successfully. Gene coding region length was 879 bp, encoding 292 amino acids with a mass of 31.66 kDa, pI was 6.5, the total number of atoms was 4457, and molecular formula was C1371H2242N3920439SI3. Conserved Domains database was used to analyze the protein conserved domains. The results showed that this protein sequence had the typical structures of plant Smh telomere binding protein subfamily including the Myb like domain located at the N-terminal and the middle histone H 1/5 like domain. The phylogenetic trees constructed by FvSmhl and other telomere binding protein which contained telobox, showed that both SMH telomere binding protein and TRF1, TRF2 belonged to the same branch and had close relationship with each other. From the analysis above, it was inferred that the cloned Fraxinus velutina smhl gene might play an important role in maintaining the structure and function of the plant telomere.