Single-molecule studies of DNA and RNA four-way junctions. (1st February 2004)

• Record Type: Journal Article
• Authors: McKinney, S.A.; Tan, E.; Wilson, T.J.; Nahas, M.K.; Déclais, A.-C.; Clegg, R.M.; Lilley, D.M.J.; Ha, T.
• Is Part Of: Biochemical Society transactions. Volume 32:Number 1(2004)
• Page Start: 41
• Page End: 45
• Publication Date: 2004-02-01
• Subjects: branch migration -- fluorescence resonance energy transfer (FRET) -- hairpin ribozyme -- Holliday junction -- RNA folding -- single-molecule spectroscopy; Biochemistry -- Congresses; 572
• DOI: 10.1042/bst0320041
• Languages: English
• ISSNs: 0300-5127

Abstract

Abstract : Branched helical junctions are common in nucleic acids. In DNA, the four-way junction (Holliday junction) is an essential intermediate in homologous recombination and is a highly dynamic structure, capable of stacking conformer transitions and branch migration. Our single-molecule fluorescence studies provide unique insight into the energy landscape of Holliday junctions by visualizing these processes directly. In the hairpin ribozyme, an RNA four-way junction is an important structural element that enhances active-site formation by several orders of magnitude. Our single-molecule studies suggest a plausible mechanism for how the junction achieves this remarkable feat; the structural dynamics of the four-way junction bring about frequent contacts between the loops that are needed to form the active site. The most definitive evidence for this is the observation of three-state folding in single-hairpin ribozymes, the intermediate state of which is populated due to the intrinsic properties of the junction.