Related Experiment Video
Updated: Aug 3, 2026

Real-time Observation of the DNA Strand Exchange Reaction Mediated by Rad51
Published on: February 13, 2019
[Specific oligonucleotide invasion into the end of DNA duplex]
Abstract:
Phenomenon of the interaction of a double-stranded DNA fragment with an oligonucleotide complementary to the end of the duplex strand was demonstrated to occur via formation of three-stranded DNA structure with an oligonucleotide invasion. It was shown that oligonucleotides complementary to the duplex ends inhibit Holliday junction formation in solutions of homologous linear DNA fragments. This effect depends on the oligonucleotide concentration, sequence and their complementarity to the duplex ends. Formation of three-stranded complexes was demonstrated using radiolabeled oligonucleotides by agarose gel-electrophoresis followed by autoradiography. Analysis of three-stranded DNA structures by chemical cleavage of non-canonical base pairs revealed that oligonucleotide invades into duplex ends via a sequential displacement mechanism and that the level of the invasion may vary considerably.
Related Concept Videos
The DNA Replication Fork
DNA Topoisomerases
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...
Translesion DNA Polymerases
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
Homologous Recombination
Single-Strand DNA Binding Proteins
Restriction Enzymes
The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some...

