Triple-stranded DNA (also known as H-DNA or Triplex-DNA) is a DNA structure in which three oligonucleotides wind around each other and form a triple helix. In triple-stranded DNA, the third strand binds to a B-form DNA (via Watson–Crick base-pairing) double helix by forming Hoogsteen base pairs or reversed Hoogsteen hydrogen bonds.

A well-established multi-stranded DNA structure, triple helical DNA (triplex DNA), both naturally occurring intramolecular H-DNA structures, and triplex-forming oligonucleotide (TFO)-targeted intermolecular triplexes will be the focus of this review.

2023年5月3日 · What is Triple Helix DNA? The triple helix is an uncommon, unconventional and atypical DNA form that occurs only when a single strand of DNA binds with the double-stranded DNA by an unusual Hoogsteen hydrogen bonding. Notedly, the third single helix binds largely to DNA major groove.

2008年12月1日 · PNA’s unique properties potentially give it several advantages over antisense DNAs and RNAs, including more versatility in binding to DNA as well as RNA, stronger binding to its target and...

2022年7月29日 · Triple Helix DNA Occasionally, DNA even comes in the form of a triple helix! In this rare genetic structure, the third strand winds around the central double helix in the larger spaces left by the original staircase shape.

Triplex-forming oligonucleotides (TFOs) are major groove ligands that target unique DNA sequences by forming DNA triple helices thanks to specific hydrogen bonding interactions between the TFO and the oligopurine strand of the duplex (Figure 2 A).

A DNA triple helix is made up of three separate DNA strands, each oriented with the sugar/phosphate backbone on the outside of the helix and the bases on the inside of the helix. The bases are the part of the molecule closest to the triple helix's axis, and the backbone is the part of the molecule farthest away from the axis.

These include three-stranded DNA triplexes and four-stranded DNA quadruplexes. Several lines of evidence suggest that multiplex structures can form in vivo, either from the addition of oligonucleotides or through the transient formation of single-stranded regions.

2008年8月1日 · Triplex-forming oligonucleotides constitute an interesting DNA sequence-specific tool that can be used to target cleaving or cross-linking agents, transcription factors or nucleases to a chosen site on the DNA.

H-DNA plays important roles in vivo and is inherently mutagenic and recombinogenic, such that elements of the H-DNA structure may be pharmacologically exploitable. In this review we discuss the biological consequences and therapeutic potential of triple helical DNA structures.