Recent progress in non-native nucleic acid modifications

Abstract

While Nature harnesses RNA and DNA to store, read and write genetic information, the inherent programmability, synthetic accessibility and wide functionality of these nucleic acids make them attractive tools for use in a vast array of applications.

Non-Canonical Helical Structure of Nucleic Acids Containing Base-Modified Nucleotides

“…Modified nucleosides at the C8 position have been incorporated into oligonucleotides to unveil the structural characteristics and biological significances [5,7,21,79]. This section reviews the major contributions of nucleoside alterations to the investigation of Z-DNA and G-quadruplexes.…”

“…These nucleic acid bases can be naturally modified or chemically synthesized. In particular, many artificially modified nucleobases are widely used with methyl, halogen, and aryl groups of purine at the C8 position [3][4][5][6] and pyrimidine at the C5 position [7][8][9] (Figure 1). Despite the numerous studies conducted on this topic, most of the properties and functions of basemodified substituents have not yet been fully determined.…”

Double-headed nucleosides: Synthesis and applications

“…Modified nucleosides are a class of organic compounds which are unnatural and have an altered/substituted nucleobase and/or a modified pentose sugar [3,4]. The synthe-tic accessibility of these organic molecules encouraged researchers to prepare sugar-modified nucleosides [5,6] and nucleobase-modified nucleosides [7,8]. Modified nucleoside monomers comprising more than one nucleobase are called double-headed nucleosides [9,10].…”

Inhibition of off-target cleavage by RNase H using an artificial cationic oligosaccharide

“…1 ASOs are classified into two types, ribonuclease H-dependent ASOs (RNase H-dependent ASOs) and RNase H-independent ASOs, and appropriate chemical modifications are necessary for each type of ASO. [2][3][4][5] RNase H is an endogenous nuclease that recognizes DNA/RNA hybrid duplexes to cleave their RNA strand. RNase H-dependent ASOs are at least partly composed of a consecutive DNA region.…”