Department of Chemistry, McGill University, Montreal, Quebec H3A 0B8, Canada.
Acc Chem Res. 2021 May 4;54(9):2287-2297. doi: 10.1021/acs.accounts.1c00125. Epub 2021 Apr 16.
This Account highlights the structural features that render 2'-deoxy-2'-fluoro-arabinonucleic acid (FANA) an ideal tool for mimicking DNA secondary structures and probing biomolecular interactions relevant to chemical biology.The high binding affinity of FANA to DNA and RNA has had implications in therapeutics. FANA can hybridize to complementary RNA, resulting in a predominant A-form helix stabilized by a network of 2'F-H8(purine) pseudohydrogen bonding interactions. We have shown that FANA/RNA hybrids are substrates of RNase H and Ago2, both implicated in the mechanism of action of antisense oligonucleotides (ASOs) and siRNA, respectvely. This knowledge has helped us study the conformational preferences of ASOs and siRNA as well as crRNA in CRISPR-associated Cas9, thereby revealing structural features crucial to biochemical activity.Additionally, FANA is of particular use in stabilizing noncanonical DNA structures. For instance, we have taken advantage of the anti N-glycosidic bond conformation of FANA monomers to induce a parallel topology in telomeric G-quadruplexes. Subsequent single-molecule FRET studies elucidated the mechanism by which these parallel G-quadruplexes are recognized and extended by telomerase. Similarly, we have utilized FANA to stabilize elusive telomeric i-motifs in the presence of concomitant parallel G-quadruplexes and under physiological conditions, thereby reinforcing their potential relevance to telomere biology. In another study, we adapted microarray technology and used FANA substitutions to enhance the binding affinity of the G-quadruplex thrombin-binding aptamer to its thrombin target.Finally, we discovered that DNA polymerases can synthesize FANA strands from DNA templates. On the basis of this property, other groups demonstrated that FANA, like DNA, can store hereditary information. They did so by engineering polymerases to efficiently transfer genetic information from DNA to FANA and retrieve it back into DNA. Subsequent studies showed that FANA could be evolved to acquire ribozyme-like endonuclease or ligase activity and to form high-affinity aptamers.Overall, the implications of these studies are remarkable because they promise a deeper understanding of human biochemistry for innovative therapeutic avenues. This Account summarizes past achievements and provides an outlook for inspiring the increased use of FANA in biological applications and fostering interdisciplinary collaborations.
该综述重点介绍了 2'-脱氧-2'-氟代阿拉伯糖核酸（FANA）的结构特征，使其成为模拟 DNA 二级结构和研究与化学生物学相关生物分子相互作用的理想工具。FANA 与 DNA 和 RNA 的高结合亲和力在治疗学方面具有重要意义。FANA 可以与互补的 RNA 杂交，形成主要为 A 型构象的螺旋，由 2'F-H8（嘌呤）假氢键相互作用网络稳定。我们已经证明，FANA/RNA 杂交体是 RNase H 和 Ago2 的底物，它们分别参与反义寡核苷酸（ASO）和 siRNA 的作用机制。这一知识帮助我们研究了 ASO 和 siRNA 以及 CRISPR 相关 Cas9 中的 crRNA 的构象偏好，从而揭示了对生化活性至关重要的结构特征。此外，FANA 在稳定非canonical DNA 结构方面特别有用。例如，我们利用 FANA 单体的反 N-糖苷键构象诱导端粒 G-四链体的平行拓扑结构。随后的单分子 FRET 研究阐明了这些平行 G-四链体被端粒酶识别和延伸的机制。同样，我们利用 FANA 在存在伴随的平行 G-四链体和生理条件下稳定难以捉摸的端粒 i- 发夹，从而加强了它们与端粒生物学的相关性。在另一项研究中，我们采用了微阵列技术并用 FANA 取代来增强凝血酶结合适体与凝血酶靶标的结合亲和力。最后，我们发现 DNA 聚合酶可以从 DNA 模板上合成 FANA 链。基于这一特性，其他研究小组证明 FANA 可以像 DNA 一样存储遗传信息。他们通过设计聚合酶从 DNA 有效地将遗传信息转移到 FANA 并将其取回 DNA 来实现这一点。随后的研究表明，FANA 可以进化获得核酶样内切核酸酶或连接酶活性，并形成高亲和力的适体。总的来说，这些研究的意义重大，因为它们有望为创新的治疗方法提供对人类生物化学的更深入了解。该综述总结了过去的成就，并对激发 FANA 在生物应用中的更多使用以及促进跨学科合作提供了展望。
