稻属中一个高度保守和组成型表达酪氨酸／丝氨酸－酸酸双特性蛋白激酶基因的克隆与分析

从水稻中克隆了一个在稻属植物中高度保守和组成型表达的丝氨酸／苏氨酸蛋白激酶基因（OsSTK）。该基因包含两个外显子和一个114bp的小内含子序列，预测编码一个419个氨基酸的蛋白质。该基因推导的氨基酸序列与其它已知序列的一致性均低于52％。利用从不同种和类型的野生稻克隆的部分该基因序列构建的系统树与野生稻的分类和进化关系相一致。OSPKN-端拥有一段富含丝氨酸、碱性氨基酸和带电荷氨基酸的特异性导肽序列，其中包含“GDGDGDGDG”短重复序列。由于该基因蛋白激酶结构域中的VIb，VIII和XI亚结构域中同时具有酪氨酸蛋白激酶和丝氨酸／苏氨酸蛋白激酶的特性，推测该基因可能同时具有催化酪氨酸和丝氨酸、苏氨酸磷酸化的双重功能。

Cloning and Analyses of a Dual Specific Serine/Thronine Protein Kinase Gene with High Conservative and Constitutive Expression in Oryza (OsSTK)

A cytoplasmic serine/thronine protein kinase gene (OsSTK), had been cloned from Oryza genus. It was found high conservative and constitutive expression in Oryza. OsSTK gene had two exons, separated by 114 bp short intron. The open reading frame of OsSTK gene that predicted encoded a 419 amino acids protein. The amino acid sequence of OsSTK had low identities (less than 53%) with any other known protein kinase. The phylogenetic tree based on the partial DNA sequences of OsSTK from different species and types of wild rice and cultivated rice, was close to the taxation system of rice. Interestingly, OsSTK had a serine, including basic amino acids and charged amino acids abundant polypeptide with a "GDGDGDGDG" sequence at N-terminal that had not been found in any other genes. OsSTK may play dual specificity that phosphorylates both serine/thronine and tyrosone, because the amino acids module of Vib, VⅢ and XI catalytic domain have both the serine/thronine and tyrosine kinase characters.