八肋游仆虫胞质核糖体蛋白基因序列特征分析

THE CHARACTERIZATION OF CYTOPLASMIC RIBOSOMAL PROTEIN GENES IN EUPLOTES OCTOCARINATUS

为了探讨八肋游仆虫(Euplotes octocarinatus)核糖体蛋白基因的数目及其结构的特殊性,研究通过生物信息学方法,对八肋游仆虫胞质核糖体蛋白进行了系统的分析。共鉴定得到98个基因编码78种不同的胞质核糖体蛋白。其中19种胞质核糖体蛋白基因发生了复制,尽管都是有功能的,但其中一个基因的表达受到限制。通过与高等真核生物比较,我们发现:八肋游仆虫核糖体蛋白eS30缺失了N端的类泛素结构域,eL6缺失了N端的Ribosomal_L6e_N结构域。另外,不同于其他高等真核生物,八肋游仆虫酸性核糖体磷酸化蛋白uL 10为碱性蛋白。研究为进一步探讨低等真核生物核糖体的组装及功能奠定了基础。

Ribosome is a ribonucleoprotein complex that is composed of rRNAs and proteins, and is responsible for thesynthesis of polypeptide chains in all living cells. Euplotes octocarinatus is a freshwater ciliate which possesses uniqueregulation of gene expression. The study of the unique features of E. octocarinatus ribosomal proteins has beenhampered by the lack of available information. In this study, we performed bioinformatic approach to conduct a systematic analysis of the CRPs of E. octocarinatus. We identified 98 genes encoding 78 different CRPs. Interestingly, 19CRP genes are present as duplicates and, while all appear to be functional, one member of each gene pair has relativelylimited expression. Compared with higher eukaryotic organisms, the ribosomal proteins eS30 and eL6 of E. octocarinatus lost ubiquitin-like domain and Ribosomal_L6e_N domain, respectively. Furthermore, the uL10 of E. octocarinatus is a basic protein. Our study lay a foundation for the future understanding of the assembling and function of ribosome in lower eukaryotic organisms.