HOLLIDAY JUNCTION

A Holliday junction is a junction between four strands of DNA. The structure is named after Robin Holliday, who proposed it in 1964[1][2][3] to account for a particular type of exchange of genetic information he observed in Ustilago maydis known as homologous recombination. Holliday junctions are highly conserved structures, from prokaryotes to mammals.[4] Mobile Holliday junctions are an intermediate in genetic recombination which are also of importance in maintaining genomic integrity.[1][5] In addition, cruciform structures involving Holliday junctions can arise to relieve helical strain in symmetrical sequences in DNA supercoils.[6] Immobile Holliday junctions were artificially created by scientists at first to study their structure as a model for natural Holliday junctions, but they also later found use as basic structural building blocks in DNA nanotechnology.