Marilley M, Pasero P
Laboratoire de Génétique GDR CNRS 976, Faculté de Médicine, Marseille, France.
Nucleic Acids Res. 1996 Jun 15;24(12):2204-11. doi: 10.1093/nar/24.12.2204.
Nucleotide sequences of DNA regions containing eukaryotic ribosomal promoters were analysed using strategies designed to reveal sequence-directed structural features. DNA curvature, duplex stability and pattern of twist angle variation were studied by computer modelling. Although ribosomal promoters are known to lack sequence homology (unless very closely related species are considered), investigation of these structural characteristics uncovered striking homologies in all the taxonomic groups examined so far. This wide conservation of DNA structures, while DNA sequence is not conserved, suggests that the determined structures are fundamental for ribosomal promoter function. Moreover, this result agrees well with the recent observations showing that RNA polymerase I transcription factors have not evolved as intensively as previously suspected.
利用旨在揭示序列导向结构特征的策略,对含有真核生物核糖体启动子的DNA区域的核苷酸序列进行了分析。通过计算机建模研究了DNA曲率、双链稳定性和扭曲角变化模式。虽然已知核糖体启动子缺乏序列同源性(除非考虑亲缘关系非常近的物种),但对这些结构特征的研究发现,在迄今为止所研究的所有分类群中都存在显著的同源性。DNA结构的这种广泛保守性,而DNA序列却不保守,这表明所确定的结构对于核糖体启动子功能至关重要。此外,这一结果与最近的观察结果非常吻合,即RNA聚合酶I转录因子的进化程度并不像之前所怀疑的那样剧烈。