一个水稻DEAD盒RNA解旋酶基因OsBIRH1的克隆鉴定及其蛋白纯化

Molecular characterization of a rice DEAD-box RNA helicase gene OsBIRH1 and purification of recombinant protein

克隆鉴定了一个水稻DEAD盒RNA解旋酶基因OsBIRH1。OsBIRH1基因全长cDNA由2167个核苷酸组成，包含1个长1926个核苷酸的开放阅读框，编码1个由641个氨基酸组成的蛋白，预测分子量为70．8kD。OsBIRHI基因位于水稻第3号染色体上，由8个外显子和7个内含子组成。预测的OsBIRH1蛋白包含DEAD盒解旋酶所特有的保守DEAD和HELICc结构域以及保守模体结构。系统进化树分析表明，OsBIRH1与拟南芥和人DEAD盒解旋酶有较高的同源性，氨基酸序列同一性为47％～54％。原核表达了OsBIRH1基因，纯化获得重组OsBIRH1融合蛋白，为OsBIRH1生化与生物学功能研究提供科学依据。

A rice gene, OsBIRH1, encoding for a DEAD-box RNA helicase, was cloned and characterized. The full-length cDNA of OsBIRH1 was composed of 2 167 nucleotides, in which including an open reading frame （ ORF ）＇ of 1 926 nucleotides in size. The predicted translation product of this ORF contains 641 amino acids with a calculated molecular weight of 70.8 kD. The OsBIRH1 gene is located on the chromosome 3 of rice genome and consists of 8 exons and 7 introns. Conserved DEAD and HELICc domains and motifs, which are characteristics of the DEAD-box RNA helicases, were identified in OsBIRH1 protein. Phylogenetic tree analysis illustrated that OsBIRHI had higher homology with Arabidopsis DEAD-box RNA hehcase and a human DEAD-box RNA helicase, sharing 47% - 54% amino acid identities. The recombinant OsBIRH1 protein was over-expressed and purified from E. coli, which will be helpful in elucidating the biochemical and biological functions of OsBIRH1 in future studies.