日本百脉根■牛儿基■牛儿基氢化酶的电子克隆及进化分析

根据物种间同源基因相对保守的特点,利用生物信息学的方法,以拟南芥牛儿基牛儿基氢化酶(GGH)基因cDNA序列为信息探针,搜索GenBank中的HTGs数据库,找到一个与之高度匹配的日本百脉根基因组DNA序列LJT46M09,用GENSCAN软件分析该序列得到一个包含2个外显子和1个内含子的基因。以此基因序列BLAST检索GenBank中的est-others数据库获得了同源的EST片段。进行EST拼接后得到该基因的cDNA序列,GenBank登录号为DQ013361,由1 389 bp核苷酸组成,具有完整的开放阅读框架(ORF),推测编码蛋白为462个氨基酸。推导的氨基酸序列与大豆、截形苜蓿、烟草、拟南芥、小麦、水稻的牛儿基牛儿基氢化酶基因氨基酸序列的一致率分别为91%、89%、84%、81%7、3%、74%。该基因与叶绿素等的生物合成有关。

In Silico Cloning and Evolution Analysis of Geranylgeranyl Hydrogenase Gene from Lotus corniculatus var.Japonicus

With the development of EST projects and bio-informatics,in silico cloning has been a new strategy of gene cloning.With Arabidopsis thaliana GGH cDNA sequence as a querying probe to search the Lotus corniculatus var.japonicus HTGs database,a highly homologous DNA sequence,which was referred as LjT46M09 clone,was obtained.The result of gene prediction with performing GENSCAN program showed that this gene contained 2 exons and 1 intron.With this predicted sequence to BLAST GenBank est-others database,many homologous EST sequences,which can be edited a unique sequence,was obtained,which was the same as the predicted sequence from genomic DNA.The full-length gene of 1 389 bp contained a complete ORF,encoding 462 amino acids.Its GenBank accession number was DQ013361.The deduced amino acid showed 91%,89%,84%,81%,73% and 74% homology with GGH from Glycine max,Medicago truncatula,Nicotiana tabacum,Arabidopsis thaliana and Triticum aestivum,respectively.This cDNA sequence was confirmed with EST sequences.