Toehold‐Mediated Strand Displacement in a Triplex Forming Nucleic Acid Clamp for Reversible Regulation of Polymerase Activity and Protein Expression

Abstract

Triplex forming oligonucleotides are used as a tool for gene regulation and in DNA nanotechnology. By incorporating artificial nucleica cids, target affinity and biological stabilitys uperior to that of naturalD NA mayb e obtained. This work demonstrates how ac himeric clamp consisting of acyclic( L)-threoninol nucleic acid (aTNA) and DNA can bind DNA and RNA by the formationof ah ighly stable triplex structure. The (L)-aTNA clamp is released from the targeta gain by the addition of ar eleasing strand in as trand displacement type of reaction. It is shown that the clamp efficientlyi nhibits Bsu and T7 RNA polymerase activity and that polymerase activity is reactivated by displacing the clamp. The clamp was successfully appliedt o the regulation of luciferase expression by reversible binding to the mRNA. When targeting as equence in the double stranded plasmid, 40 %d ownregulation of protein expression is achieved.[a] Dr.

Thermo-Programmed Synthetic DNA-Based Receptors

“…Finally, the approach is also relevant for RNA sequences that can form triplex structures in a similar way to DNA sequences (Figure S8). − …”

Functionalized Acyclic (l)‐Threoninol Nucleic Acid Four‐Way Junction with High Stability In Vitro and In Vivo

“…were the first to report on the synthesis of aTNA and that aTNA forms an antiparallel homo‐duplex of high stability [17, 18] . We have later shown that aTNA forms highly stable sandwich type triplex structures with DNA and RNA and that aTNA is capable of forming i‐motifs and G‐quadruplexes [19–22] . This artificial oligonucleotide furthermore forms parallel duplexes with DNA and RNA, presumably because of an optimal rigidity [17] .…”

Acyclic Nucleic Acids with Phosphodiester Linkages—Synthesis, Properties and Potential Applications

“…The triplex formation phenomenon has been used for reversible regulation of polymerase activity and protein expression [61]. It was found that a construct of two acyclic L-aTNA homopyrimidine segments (linked to a hexaethylene glycol linker) and DNA (directly linked to an L-aTNA segment) can bind DNA and RNA by forming a highly stable triplex structure.…”