Fine structure of ribosomal RNA. III. Location of evolutionarily conserved regions within ribosomal DNA.
Fine structure of ribosomal RNA. III. Location of evolutionarily conserved regions within ribosomal DNA.
复制标题
核糖体RNA的精细结构。
DOI：
10.1016/0022-2836(80)90109-6
复制
发表时间：
1980
影响因子：
5.6
通讯作者：
S. Gerbi
中科院分区：
文献类型：
--
作者：
R. Gourse;S. Gerbi
为了确定核糖体RNA内的功能区域，我们已经确定了在进化过程中保守的分子区域。我们以前的研究表明，不同真核生物的rRNA之间存在进化保守性，并且远亲物种之间保守的序列是近亲物种之间保守序列的一个子集。在目前的工作中，我们采用DNA-DNA和DNA-RNA杂交技术，定位这些保守的区域映射限制性片段长度为50至300个碱基对克隆非洲爪蟾核糖体DNA。我们的实验只在编码区内检测到进化保守性，这表明如果间隔区内有任何保守性，这些序列必须非常短。保护区可以根据进化距离或两个物种之间的保护程度来分类。18 SrRNA的3'端和28 SrRNA的3'端在进化距离上有3个保守区，即在地球化学和X之间。光滑。此外，188和28 S rRNA中心部分的几个片段在酵母和非洲爪蟾之间的保守程度是例外的。我们已经能够将我们定义为保守的区域与某些结构或功能角色相关联，例如翻译的起始，与转移RNA的可能相互作用，rRNA甲基化以及插入序列中断某些真核rRNA的位点。因此，这些研究有助于在近11，000个碱基X中定义相对较短（小于300个碱基对）的片段。laevisrDNA重复单元，值得进一步研究。
In order to define functional regions within ribosomal RNA, we have identified areas of the molecule which have been conserved during evolution. Our previous studies showed that there is evolutionary conservation between the rRNAs of different eukaryotes and that the sequences conserved between distantly related species are a subset of those conserved between closely related species. In the present work, we have employed DNA-DNA and DNA-RNA hybridization techniques to localize these conserved regions to mapped restriction fragments 50 to 300 base-pairs in length within clonedXenopus laevisribosomal DNA. Our experiments have detected evolutionary conservation only within the coding regions, suggesting that if there is any conservation within the spacers, these sequences must be very short. Regions of conservation can be classified either by evolutionarydistanceor by theextentof conservation between two species. Three regions, including one near the 3' end of 18 S and two near the 3' end of 28 S rRNA are conserved over great evolutionary distance, that is between EscherichiacoliandX. laevis. In addition, several fragments in the central portions of the 188 and 28 S rRNAs are exceptional in the extent of their conservation between yeast andXenopus. We have been able to correlate the regions we have defined as conserved with certain structural or functional roles, such as initiation of translation, possible interaction with transfer RNA, rRNA methylation, and the site where intervening sequences interrupt some eukaryotic rRNAs. As a result, these studies serve to define relatively short (less than 300 base-pairs) segments within the almost 11,000 baseX. laevisrDNA repeat unit which are worthy of further investigation.