title: Interactions between Flavins and Quadruplex Nucleic Acids.
abstract: Quadruplex nucleic acids are widespread in genomes. They influence processes such as transcription, translation, replication, recombination, and the regulation of gene expression. Several synthetic ligands have been demonstrated to target quadruplex nucleic acids. However, only very few metabolites have been reported to interact with quadruplexes. In principle, an intracellular metabolite that selectively binds to four-stranded sequences could modulate quadruplex formation, stability, and thus functions in a riboswitch (or deoxyriboswitch) manner. Here we report quadruplex interactions with flavin derivatives such as FMN and FAD. The affinities were highest with parallel quadruplexes, with low (14-20 μm) dissociation constants. Taking into account combined intracellular flavin concentrations of 243 μm in E. coli, the observed interactions in principle open up the possibility of flavin levels affecting gene expression and other processes by modulating quadruplex formation.
authors.affiliation: Department of Chemistry and Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, P. O. Box: 630, 78457, Konstanz, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Merkle
authors.affiliation: Department of Chemistry and Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, P. O. Box: 630, 78457, Konstanz, Germany.
authors.forename: Malte
authors.initials: M
authors.lastname: Sinn
authors.affiliation: Department of Chemistry and Research School Chemical Biology, University of Konstanz, Universitätsstrasse 10, P. O. Box: 630, 78457, Konstanz, Germany. joerg.hartig@uni-konstanz.de.
authors.forename: Jörg S
authors.initials: JS
authors.lastname: Hartig
mesh_terms: D001483:Base Sequence; D002942:Circular Dichroism; D005415:Flavins / Q000737:chemistry*; D054856:G-Quadruplexes; D007700:Kinetics; D009690:Nucleic Acid Conformation; D058928:Riboswitch; D020349:Surface Plasmon Resonance
chemical_list: D005415:Flavins; D058928:Riboswitch
keywords: DNA structures; FAD; flavin metabolism; nucleic acids; riboswitch