title: Structure of a class II preQ1 riboswitch reveals ligand recognition by a new fold.
abstract: PreQ1 riboswitches regulate genes by binding the pyrrolopyrimidine intermediate preQ1 during the biosynthesis of the essential tRNA base queuosine. We report what is to our knowledge the first preQ1-II riboswitch structure at 2.3-Å resolution, which uses a previously uncharacterized fold to achieve effector recognition at the confluence of a three-way helical junction flanking a pseudoknotted ribosome-binding site. The results account for translational control mediated by the preQ1-II riboswitch class and expand the known repertoire of ligand-binding modes used by regulatory RNAs.
authors.affiliation: Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Liberman
authors.forename: Mohammad
authors.initials: M
authors.lastname: Salim
authors.forename: Jolanta
authors.initials: J
authors.lastname: Krucinska
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Wedekind
mesh_terms: D001665:Binding Sites; D002151:Calorimetry; D007700:Kinetics; D052201:Lacticaseibacillus rhamnosus / Q000378:metabolism; D008024:Ligands; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D017510:Protein Folding; D017433:Protein Structure, Secondary; D012313:RNA / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D058928:Riboswitch; D014961:X-Ray Diffraction
chemical_list: D008024:Ligands; D012333:RNA, Messenger; D058928:Riboswitch; D012313:RNA