微小贾第虫核糖体DNA操纵子的全核苷酸序列及大亚基rRNA的结构

The nucleotide sequence of the entire ribosomal DNA operon and the structure of the large subunit rRNA of Giardia muris.

作者信息

van Keulen H, Gutell R R, Campbell S R, Erlandsen S L, Jarroll E L

机构信息

Department of Biology, Cleveland State University, OH 44115.

出版信息

J Mol Evol. 1992 Oct;35(4):318-28. doi: 10.1007/BF00161169.

DOI:10.1007/BF00161169

PMID:1404417

Abstract

The total nucleotide sequence of the rDNA of Giardia muris, an intestinal protozoan parasite of rodents, has been determined. The repeat unit is 7668 basepairs (bp) in size and consists of a spacer of 3314 bp, a small-subunit rRNA (SSU-rRNA) gene of 1429, and a large-subunit rRNA (LSU-rRNA) gene of 2698 bp. The spacer contains long direct repeats and is heterogeneous in size. The LSU-rRNA of G. muris was compared to that of the human intestinal parasite Giardia duodenalis, to the bird parasite Giardia ardeae, and to that of Escherichia coli. The LSU-rRNA has a size comparable to the 23S rRNA of E. coli but shows structural features typical for eukaryotes. Some variable regions are typically small and account for the overall smaller size of this rRNA. The structure of the G. muris LSU-rRNA is similar to that of the other Giardia rRNA, but each rRNA has characteristic features residing in a number of variable regions.

摘要

已确定鼠贾第虫（一种啮齿动物肠道原生动物寄生虫）核糖体DNA（rDNA）的完整核苷酸序列。重复单元大小为7668个碱基对（bp），由一个3314 bp的间隔区、一个1429个碱基的小亚基核糖体RNA（SSU-rRNA）基因和一个2698 bp的大亚基核糖体RNA（LSU-rRNA）基因组成。间隔区包含长的正向重复序列，且大小不均一。将鼠贾第虫的LSU-rRNA与人类肠道寄生虫十二指肠贾第虫、鸟类寄生虫阿氏贾第虫以及大肠杆菌的LSU-rRNA进行了比较。鼠贾第虫的LSU-rRNA大小与大肠杆菌的23S rRNA相当，但具有真核生物典型的结构特征。一些可变区通常较小，这也是该rRNA整体尺寸较小的原因。鼠贾第虫LSU-rRNA的结构与其他贾第虫rRNA相似，但每种rRNA在多个可变区都有特征性特点。