Sequence analysis of 28S ribosomal DNA from the amphibian Xenopus laevis.
Sequence analysis of 28S ribosomal DNA from the amphibian Xenopus laevis.
复制标题
两栖动物非洲爪蟾 28S 核糖体 DNA 的序列分析。
DOI：
10.1093/nar/11.22.7795
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发表时间：
1983
影响因子：
14.9
通讯作者：
S. Gerbi
中科院分区：
文献类型：
--
作者：
V. Ware;B. Tague;Graham Clark;R. Gourse;Reindert C Brand;S. Gerbi
我们测定了非洲爪哇28S rDNA的全序列(4110bp)。为了定位rDNA中进化保守的区域，我们将非洲爪哇的28S序列与酵母、绒毛霉和大肠杆菌中的同源rDNA序列进行了比较。序列同源性的许多区域分布在所有四种生物的rDNA的整个长度上。这些保守区域比rDNA的其余部分具有更高的A+T碱基组成。与大肠杆菌23S rDNA相比，非洲爪哇的28S rDNA插入了九个主要的序列区域。这些插入片段的总碱基组成为83%的G+C，这通常是非洲爪哇28S rDNA总体上G+C含量高(66%)的原因。虽然插入序列的长度不同，但在酵母26S、绒毛霉26S和非洲爪哇28S rDNA中发现的插入片段位于相同的相对位置。在一个插入片段中，有25个碱基在不同的真核生物之间完全保守，这表明该区域对真核核糖体是重要的。其他插入片段在序列上因物种不同而不同，可能发挥功能作用，也可能不起作用。
We have determined the complete nucleotide sequence of Xenopus laevis 28S rDNA (4110 bp). In order to locate evolutionarily conserved regions within rDNA, we compared the Xenopus 28S sequence to homologous rDNA sequences from yeast, Physarum, and E. coli. Numerous regions of sequence homology are dispersed throughout the entire length of rDNA from all four organisms. These conserved regions have a higher A + T base composition than the remainder of the rDNA. The Xenopus 28S rDNA has nine major areas of sequence inserted when compared to E. coli 23S rDNA. The total base composition of these inserts in Xenopus is 83% G + C, and is generally responsible for the high (66%) G + C content of Xenopus 28S rDNA as a whole. Although the length of the inserted sequences varies, the inserts are found in the same relative positions in yeast 26S, Physarum 26S, and Xenopus 28S rDNAs. In one insert there are 25 bases completely conserved between the various eukaryotes, suggesting that this area is important for eukaryotic ribosomes. The other inserts differ in sequence between species and may or may not play a functional role.