title: Hyperreactivity of adenines and conformational flexibility of a translational repression site.
abstract: We have used a diethylpyrocarbonate (DEPC) modification [(1976) Prog. Nucl. Acids Res. 16, 189-262] to probe the accessibility of adenines essential for coat protein binding in the MS2 translational operator [(1983) Biochemistry 22, 2601-2610, 2610-2615, 4723-4730; (1987) Biochemistry 26, 1563-1568]. The essential adenines are apparently hyperreactive with this reagent relative to other sites within the same molecule. Variation of ionic strength, pH and divalent cation concentrations reveal the existence of two distinct conformers of the RNA operator as judged by DEPC reactivity. We propose that the hyperreactivity observed is due to the participation of neighbouring bases in the DEPC modification reaction and can be used as a novel structural probe.
authors.affiliation: Department of Genetics, School of Chemistry, University of Leeds, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Talbot
authors.forename: G
authors.initials: G
authors.lastname: Medina
authors.forename: C W
authors.initials: CW
authors.lastname: Fishwick
authors.forename: I
authors.initials: I
authors.lastname: Haneef
authors.forename: P G
authors.initials: PG
authors.lastname: Stockley
mesh_terms: D000225:Adenine / Q000378:metabolism*; D001435:Bacteriophages / Q000378:metabolism; D001483:Base Sequence; D002213:Capsid / Q000235:genetics / Q000378:metabolism; D004047:Diethyl Pyrocarbonate / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010957:Plasmids; D014176:Protein Biosynthesis; D012313:RNA / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D012313:RNA; D000225:Adenine; D004047:Diethyl Pyrocarbonate