DNA tetraplex formation studied with fluorescence resonance energy transfer.
It is emerging that DNA tetraplexes are pivotal for many major cellular processes, and techniques that assess their structure and nature to the point are under development. Here we show how the structural conversion of largely unstructured single-stranded DNA molecules into compact intrastrand DNA tetraplexes can be monitored by fluorescence resonance energy transfer. We recently reported that intrastrand tetraplex formation takes place in a nuclease hypersensitive element upstream of the human c-myc proto-oncogene. Despite the highly repetitive guanine-rich sequence of the hypersensitive element, fluorescence resonance energy transfer measurements indicate that only one well defined tetraplex structure forms therein. The proposed structure, which is specifically stabilized by potassium ions in vitro, has a core of three stacked guanine tetrads that is capped by two intrastrand A-T base pairs.
Simonsson
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T
Department of Biochemistry, Lundberg Institute, Chalmers University of Technology, Box 462, SE 405 30 Göteborg, Sweden. Tomas@bcbp.chalmers.se
Sjöback
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R
D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000235:genetics; D004735:Energy Transfer; D054856:G-Quadruplexes; D016259:Genes, myc; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics*; D013050:Spectrometry, Fluorescence / Q000379:methods
D004277:DNA, Single-Stranded; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc; D004247:DNA