摘要
RNA编辑是一种特殊的转录后加工过程,是陆生植物叶绿体基因组在转录后水平上调控基因表达的一种重要方式。为了给研究叶绿体基因RNA编辑功能及其发生机制提供依据,以栽培大麦为研究对象,采用生物信息学方法对其叶绿体的83个蛋白编码基因的RNA编辑位点进行预测和分析。结果在16个基因中发现了37个RNA编辑位点,且均为C到U的转换,其中5个发生在密码子的第一位,32个发生在密码子的第二位,未发现发生在密码子第三位的RNA编辑;采用blast工具,与NCBI数据库中的大麦EST序列进行了对比,确定其中的34个编辑位点是真实存在的,其中ndhB基因最多,为8个编辑位点;进一步利用生物信息学工具分析了ndhB中RNA编辑对其编码蛋白质的跨膜结构域和二级结构的影响,结果表明,ndhB-467的编辑会引起蛋白质跨膜结构的增加,ndhB-149的编辑会引起蛋白质二级结构的改变。最后还将预测的大麦编辑位点与其他4种禾本科叶绿体的编辑位点进行了比较。
RNA editing is one of the most important approaches to regulate the gene expression at post-transcriptional levels in the chloroplast genomes of land plants. In this study, we predicted and i- dentified the RNA editing sites of 83 chloroplast protein-coding genes of barley using the bioinformat- ics approach. Results showed that 37 editing sites were found from 16 genes, and all of them are C to U conversion. Among them, 5 sites located in the first position of codon, 32 sites locating in the sec- ond position of codon and no RNA editing sites were found in the third position of codon. Through blasting with the EST sequences of barley in NCBI database, 34 sites in 16 genes were validated as the actual RNA editing sites, of which the ndhB had the most editing site with the number of 9. Further- more, the second structures and the transmenbrane domains of edited ndhB protein were analyzed u- sing the bioinformatics methods. Results indicated that editing in ndhB-467 resulted in an increase in transmenbrane protein domains and editing in ndhB-149 change the secondary structure. Finally, the comparison analysis of the editing sites in barley with other 5 grass chloroplast genomes was also per- formed. Our study analyzed the composition and distribution of RNA editing in barley chloroplast genome comprehensively, which provided the useful information for exploring the function and mecha nism of RNA editing, as well as for revealing the origin and molecular evolution of RNA editing in or ganelle genomes.
出处
《麦类作物学报》
CAS
CSCD
北大核心
2013年第6期1071-1077,共7页
Journal of Triticeae Crops
