title: Fluorescence probing of T box antiterminator RNA: insights into riboswitch discernment of the tRNA discriminator base.
abstract: The T box transcription antitermination riboswitch is one of the main regulatory mechanisms utilized by Gram-positive bacteria to regulate genes that are involved in amino acid metabolism. The details of the antitermination event, including the role that Mg(2+) plays, in this riboswitch have not been completely elucidated. In these studies, details of the antitermination event were investigated utilizing 2-aminopurine to monitor structural changes of a model antiterminator RNA when it was bound to model tRNA. Based on the results of these fluorescence studies, the model tRNA binds the model antiterminator RNA via an induced-fit. This binding is enhanced by the presence of Mg(2+), facilitating the complete base pairing of the model tRNA acceptor end with the complementary bases in the model antiterminator bulge.
authors.affiliation: Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Means
authors.forename: Crystal M
authors.initials: CM
authors.lastname: Simson
authors.forename: Shu
authors.initials: S
authors.lastname: Zhou
authors.forename: Aaron A
authors.initials: AA
authors.lastname: Rachford
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Rack
authors.forename: Jennifer V
authors.initials: JV
authors.lastname: Hines
mesh_terms: D020121:5' Untranslated Regions; D005453:Fluorescence; D015964:Gene Expression Regulation, Bacterial; D006094:Gram-Positive Bacteria / Q000235:genetics*; D008274:Magnesium / Q000737:chemistry / Q000378:metabolism; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013728:Terminator Regions, Genetic
chemical_list: D020121:5' Untranslated Regions; D012329:RNA, Bacterial; D012343:RNA, Transfer; D008274:Magnesium