Thermodynamic investigation of kissing-loop interactions
Thermodynamic investigation of kissing-loop interactions
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DOI：
10.1016/j.biochi.2018.11.012
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发表时间：
2019-02-01
期刊：
影响因子：
3.9
通讯作者：
Marky, Luis A.
中科院分区：
文献类型：
--
作者：
Carr, Carolyn E.;Marky, Luis A.
接吻环相互作用（KLI）是逆转录病毒二聚化、类病毒复制、mRNA和核糖开关中至关重要的常见基序。此外，KLI目前用于各种生物技术应用，如适体传感器、RNA支架和稳定治疗用疫苗。在这里，我们描述了一个基本的分子内DNA的热力学能够从事KLI，由两个发夹连接一个灵活的接头。每个发夹环具有理论上能够参与KLI的五核苷酸互补序列。在每个环的两侧是两个胸腺嘧啶，它们不会参与接吻，但提供更大的灵活性和最佳的KLI定位。我们的研究结果表明，KLI发生，即使在生理盐水平，KLI不改变两个茎结构的热力学和稳定性。KLI并不涉及所有五个核苷酸，或者至少每个碱基对堆叠没有完全接触。在吻合复合体的底部添加第二条互补链会消除柔性并导致茎的不稳定。这种柔性较低的复合物的KLI得以维持，但T-M减少，表明其形成受到异位惩罚。(C)2018 Elsevier B. V.和法国生物化学与生物分子学会（SFBBM）。All rights reserved.
Kissing loop interactions (KLIs) are a common motif that is critical in retroviral dimerization, viroid replication, mRNA, and riboswitches. In addition, KLIs are currently used in a variety of biotechnology applications, such as in aptamer sensors, RNA scaffolds and to stabilize vaccines for therapeutics. Here we describe the thermodynamics of a basic intramolecular DNA capable of engaging in a KLI, consisting of two hairpins connected by a flexible linker. Each hairpin loop has a five-nucleotide complementary sequence theoretically capable of engaging in a KLI. On either side of each loop is two thymines which will not engage in kissing but are present to provide more flexibility and optimal KLI positioning. Our results suggest that the KLI occurs even at physiological salt levels, and that the KLI does not alter the thermodynamics and stability of the two stem structures. The KLI does not involve all five nucleotides, or at least each base-pair stack is not making full contact. Adding a second strand complementary to the bottom of the kissing complex removes flexibility and causes destabilization of the stems. The KLI of this less flexible complex is maintained but the T-M is reduced, indicating an entopic penalty to its formation. (C) 2018 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.