Demkovičová Erika, Bauer Ľuboš, Krafčíková Petra, Tlučková Katarína, Tóthova Petra, Halaganová Andrea, Valušová Eva, Víglaský Viktor
Department of Biochemistry, Institute of Chemistry, Faculty of Sciences, P. J. Šafárik University, 04001 Kosice, Slovakia.
Department of Biological Sciences/RNA Institute, University at Albany, SUNY, Albany, NY 12222, USA.
J Nucleic Acids. 2017;2017:9170371. doi: 10.1155/2017/9170371. Epub 2017 Dec 28.
The human telomeric and protozoal telomeric sequences differ only in one purine base in their repeats; TTAGGG in telomeric sequences; and TTGGGG in protozoal sequences. In this study, the relationship between G-quadruplexes formed from these repeats and their derivatives is analyzed and compared. The human telomeric DNA sequence G(TAG) and related sequences in which each adenine base has been systematically replaced by a guanine were investigated; the result is repeats. The substitution does not affect the formation of G-quadruplexes but may cause differences in topology. The results also show that the stability of the substituted derivatives increased in sequences with greater number of substitutions. In addition, most of the sequences containing imperfections in repeats which were analyzed in this study also occur in human and genomes. Generally, the presence of G-quadruplex structures in any organism is a source of limitations during the life cycle. Therefore, a fuller understanding of the influence of base substitution on the structural variability of G-quadruplexes would be of considerable scientific value.
人类端粒序列和原生动物端粒序列在其重复序列中仅相差一个嘌呤碱基；端粒序列中的TTAGGG；原生动物序列中的TTGGGG。在本研究中，分析并比较了由这些重复序列及其衍生物形成的G-四链体之间的关系。研究了人类端粒DNA序列G(TAG)以及其中每个腺嘌呤碱基已被鸟嘌呤系统取代的相关序列；结果是重复序列。这种取代不影响G-四链体的形成，但可能导致拓扑结构的差异。结果还表明，取代衍生物的稳定性在取代数量较多的序列中增加。此外，本研究中分析的大多数含有重复序列缺陷的序列也存在于人类和基因组中。一般来说，任何生物体中G-四链体结构的存在都是生命周期中的限制来源。因此，更全面地了解碱基取代对G-四链体结构变异性的影响具有相当大的科学价值。
