橡胶草异戊烯焦磷酸异构酶基因的电子克隆及分析

In silicon cloning and bioinformatic analysis of isopentenyl diphosphate isomerase genes in Taraxacum kok-saghyz

利用电子克隆方法获得两条橡胶草异戊烯焦磷酸异构酶基因(IDI)的cDNA序列和编码区基因组序列,分别命名为TkIDI1和TkIDI2,并采用生物信息学方法对该基因及其编码蛋白进行系统进化、亚细胞定位、活性位点、高级结构等方面的预测和分析。结果显示,TkIDI1的cDNA序列长度为980 bp,包含一个696 bp的开放读码框(ORF),编码232个氨基酸,预测定位于内质网或叶绿体上;TkIDI2的cDNA序列长度为1 038 bp,包含一个843 bp的ORF,编码281个氨基酸,预测定位于线粒体或叶绿体;而他们的截短转录本蛋白定位于胞质中,且都具有过氧化物酶体定位信号。结构分析表明TkIDI1和TkIDI2与植物IDI蛋白同源,活性位点保守,高级结构与其他植物的IDI均具有高度的相似性。

Two isopentenyl diphosphate isomerase genes （TklDI1 and TklDI2） were obtained successfully from Ta- raxacum kok-saghyz using in silicon cloning technique. Some characters of the IDI gene and encoded protein se- quences were predicted and analyzed by the bioinformatics methods in the following aspects, such as phylogenetic tree, signal peptide, localization sites in cells, location of active sites, secondary and tertiary structure. Results showed that TklDI1 （980 bp） contains a complete ORF （696 bp） encoding 232 amino acid and was predicted to locate at endoplasmic reticulum or chloroplast; TklDI2 （1 038 bp） contains a complete ORF （843 bp） encoding 281 amino acid and was predicted to locate at mitochondrion or chloroplast; their truncated transcript productions were the cytoplasm located and presented PTS1 predicted as peroxisomal targeting. Protein structure prediction sug- gested that TklDIs （TklDI1 and TklDI2） are highly homologous to other IDIs originate from various plants, and ex- hibit similar location of active sites and protein structure.