梨贝壳杉烯氧化酶基因PpKO的克隆及生物信息学分析

以黄金梨（Pyrus pyrifolia Nakai）茎尖为试材，应用同源克隆和RACE方法从梨茎尖中克隆到赤霉素合成代谢的关键酶：内根-贝壳杉烯氧化酶（KO）基因cDNA的全长序列，命名为PpKO，GenBank登录号为：HM003112，其长度为1 752 bp。PpKO的开放阅读框（ORF）编码515个氨基酸，相对分子量为59.007 kD，等电点为7.19。氨基酸同源性分析表明，PpKO与已报道的其它植物的KO氨基酸序列具有59.4% ~ 95.9%相似性；氨基酸聚类分析表明，梨和苹果首先聚类，其次是草莓；生物信息学分析表明：PpKO含有细胞色素P450核心功能域FXXGXRXCXG和氨基端的跨膜结构域。

Cloning and Bioinformatics Analysis of ent-Kaurene Oxidase Gene PpKO in Pear(Pyrus pyrifolia Nakai)

Ent-kaurene oxidase（KO）is a critical enzyme in the pathway of gibberellins biosynthesis. In this research，ent-kaurene oxidase gene in pear，designated as PpKO（GenBank accession number： HM003112），was isolated from‘Whangkeumbae’（Pyrus pyrifolia Nakai）stem apical tissue by homologous cloning and RACE technology. The full cDNA was 1 752 bp in length with an open reading frame（ORF）of 1 548 bp encoding a protein of 515 amino acids. Molecular weight and isoelectric point of the protein was 59.007 kD and 7.19，respectively. Amino acids homology analysis indicated that the sequence had 59.4%–95.9% similarity with those of other reported plants. Amino acids cluster analysis showed that KO from apple was clustered together with PpKO firstly，and followed by that from strawberry. Bioinformatics analysis exhibited that PpKO contained a core functional domain of cytochrome P450（FXXGXRXCXG）and transmembrane region near the N-terminus.