title: DNA metastability and biological regulation: conformational dynamics of metastable omega-DNA bulge loops.
abstract: Dynamic interchange between DNA conformations, including metastable states, can be of importance to biological function. In this study, we use a combination of spectroscopic and calorimetric techniques to detect and characterize kinetically trapped, metastable states in strand exchange and strand displacement reactions for bulge loop DNA conformations, here referred to as Omega-DNAs. We show that such metastable, Omega-DNA bulge loop states can stably coexist below 50 degrees C, while rearranging irreversibly at elevated temperatures to thermodynamically more stable states. Such dynamic interchange between metastable and globally stable DNA conformational states can be of importance in biological regulatory mechanisms.
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers--The State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854, USA.
authors.forename: Jens
authors.initials: J
authors.lastname: Völker
authors.forename: Horst H
authors.initials: HH
authors.lastname: Klump
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Breslauer
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000235:genetics / Q000528:radiation effects; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation / Q000528:radiation effects; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000235:genetics / Q000528:radiation effects; D013057:Spectrum Analysis; D013696:Temperature; D013816:Thermodynamics; D014466:Ultraviolet Rays
chemical_list: D009838:Oligodeoxyribonucleotides; D004247:DNA