Abagyan R A, Mironov V N, Chernov B K, Chuprina V P, Ulyanov A V
Engelhardt Institute of Molecular Biology, USSR Academy of Sciences, Moscow.
Nucleic Acids Res. 1990 Feb 25;18(4):989-92. doi: 10.1093/nar/18.4.989.
Double stranded multimers (C2A6C2)n, (C2A6G2)n and (G2A6G2)n were prepared from chemically synthesized oligonucleotides to study the influence of sequences flanking the An tract on the curvature of DNA. All these duplexes, including polypurine.polypyrimidine one, exhibit strong retardation in polyacrylamide gel which is indicative of pronounced DNA curvature. It has been proposed previously that among the bends at the boundary with the oligo(A) tract two types should be distinguished: 5'-bends and 3'-bends (Koo et al., 1986) This distinction was deduced from different relative mobilities of two specially designed sequences having phased 5'-bends and 3'-bends, respectively. Our data indicate that the substitutions of nucleotides at both 5' and 3' boundaries of A6 tract result in comparable changes in relative mobility. Therefore, for B-B' bends it is important to take into account not only whether they are at the 5' or 3' end of an oligo(dA) tract, but also the particular sequences at the boundaries of this tract.
通过化学合成的寡核苷酸制备了双链多聚体（C2A6C2）n、（C2A6G2）n和（G2A6G2）n，以研究富腺嘌呤序列（An序列）侧翼序列对DNA弯曲度的影响。所有这些双链体，包括聚嘌呤-聚嘧啶双链体，在聚丙烯酰胺凝胶中都表现出强烈的滞留现象，这表明DNA有明显的弯曲。先前有人提出，在与寡聚（A）序列边界处的弯曲中，应区分两种类型：5'-弯曲和3'-弯曲（Koo等人，1986年）。这种区分是从分别具有相位5'-弯曲和3'-弯曲的两个特殊设计序列的不同相对迁移率推导出来的。我们的数据表明，A6序列5'和3'边界处的核苷酸替换导致相对迁移率发生类似变化。因此，对于B-B'弯曲，不仅要考虑它们是在寡聚（dA）序列的5'端还是3'端，还要考虑该序列边界处的特定序列。
