Kaushik Mahima, Kaushik Shikha, Roy Kapil, Singh Anju, Mahendru Swati, Kumar Mohan, Chaudhary Swati, Ahmed Saami, Kukreti Shrikant
Cluster Innovation Centre, University of Delhi, Delhi, India.
Nucleic Acids Research Laboratory, Department of Chemistry, University of Delhi, Delhi, India.
Biochem Biophys Rep. 2016 Jan 28;5:388-395. doi: 10.1016/j.bbrep.2016.01.013. eCollection 2016 Mar.
Structural polymorphism of DNA has constantly been evolving from the time of illustration of the double helical model of DNA by Watson and Crick. A variety of non-canonical DNA structures have constantly been documented across the globe. DNA attracted worldwide attention as a carrier of genetic information. In addition to the classical Watson-Crick duplex, DNA can actually adopt diverse structures during its active participation in cellular processes like replication, transcription, recombination and repair. Structures like hairpin, cruciform, triplex, G-triplex, quadruplex, i-motif and other alternative non-canonical DNA structures have been studied at length and have also shown their occurrence. This review mainly focuses on non-canonical structures adopted by DNA oligonucleotides which have certain prerequisites for their formation in terms of sequence, its length, number and orientation of strands along with varied solution conditions. This conformational polymorphism of DNA might be the basis of different functional properties of a specific set of DNA sequences, further giving some insights for various extremely complicated biological phenomena. Many of these structures have already shown their linkages with diseases like cancer and genetic disorders, hence making them an extremely striking target for structure-specific drug designing and therapeutic applications.
自沃森和克里克阐明DNA双螺旋模型以来，DNA的结构多态性一直在不断演变。全球范围内不断有各种非经典DNA结构被记录下来。DNA作为遗传信息的载体引起了全世界的关注。除了经典的沃森-克里克双链体，DNA在积极参与复制、转录、重组和修复等细胞过程时，实际上可以呈现出多种结构。诸如发夹、十字形、三链体、G-三链体、四链体、i-基序等结构以及其他非经典DNA结构已被深入研究，并且也已证明它们的存在。本综述主要关注DNA寡核苷酸所采用的非经典结构，这些结构在序列、长度、链的数量和方向以及不同的溶液条件方面形成有一定的先决条件。DNA的这种构象多态性可能是一组特定DNA序列不同功能特性的基础，进一步为各种极其复杂的生物学现象提供了一些见解。其中许多结构已经显示出它们与癌症和遗传疾病等疾病的关联，因此使其成为结构特异性药物设计和治疗应用的极具吸引力的靶点。
