Nucleotide contributions to the structural integrity and DNA replication initiation activity of noncoding y RNA.
Nucleotide contributions to the structural integrity and DNA replication initiation activity of noncoding y RNA.
复制标题
核苷酸对非编码 y RNA 的结构完整性和 DNA 复制起始活性的贡献。
作者：
I. Wang;M. P. Kowalski;Alexander R. Langley;R. Rodriguez;S. Balasubramanian;S. Hsu;T. Krude
非编码Y rna是小的茎环rna，参与不同的细胞过程，包括DNA复制的调节。在脊椎动物Y rna的上茎中有一个进化上保守的小区域，它对染色体DNA复制的起始起着至关重要的作用。在这里，我们提供了生理条件下这种必要的RNA结构域的结构功能分析。溶液态核磁共振和远紫外圆二色光谱表明，人Y1 RNA的上茎域采用局部不稳定的a型螺旋结构，涉及8个沃森-克里克碱基对。在这个螺旋中，两个G:C碱基对即使在高温下也高度稳定，因此可以作为夹子来维持螺旋的局部结构。这两个稳定的G:C碱基对构成了位于它们中间的三个不稳定碱基对。系统替代诱变导致有序a型螺旋结构的破坏和DNA复制起始活性的丧失，从而在折叠稳定性和功能之间建立了正相关关系。因此，我们的数据为该RNA结构域中关键核苷酸的进化保护提供了结构基础，这些核苷酸在DNA复制起始期间对非编码Y RNA的功能至关重要。
Noncoding Y RNAs are small stem-loop RNAs that are involved in different cellular processes, including the regulation of DNA replication. An evolutionarily conserved small domain in the upper stem of vertebrate Y RNAs has an essential function for the initiation of chromosomal DNA replication. Here we provide a structure-function analysis of this essential RNA domain under physiological conditions. Solution state nuclear magnetic resonance and far-ultraviolet circular dichroism spectroscopy show that the upper stem domain of human Y1 RNA adopts a locally destabilized A-form helical structure involving eight Watson-Crick base pairs. Within this helix, two G:C base pairs are highly stable even at elevated temperatures and therefore may serve as clamps to maintain the local structure of the helix. These two stable G:C base pairs frame three unstable base pairs, which are located centrally between them. Systematic substitution mutagenesis results in a disruption of the ordered A-form helical structure and in the loss of DNA replication initiation activity, establishing a positive correlation between folding stability and function. Our data thus provide a structural basis for the evolutionary conservation of key nucleotides in this RNA domain that are essential for the functionality of noncoding Y RNAs during the initiation of DNA replication.
DOI：
10.1073/pnas.89.20.9734
发表时间：
1992-10-15
影响因子：
11.1
作者：
LORET, EP;GEORGEL, P;HO, PS
通讯作者：
HO, PS
DOI：
10.1073/pnas.81.7.1996
发表时间：
1984-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
WOLIN, SL;STEITZ, JA
通讯作者：
STEITZ, JA
影响因子：
7
作者：
Crooks, GE;Hon, G;Brenner, SE
通讯作者：
Brenner, SE