title: Exploiting preQ(1) riboswitches to regulate ribosomal frameshifting.
abstract: Knowing the molecular details of the interaction between riboswitch aptamers and their corresponding metabolites is important to understand gene expression. Here we report on a novel in vitro assay to study preQ(1) riboswitch aptamers upon binding of 7-aminomethyl-7-deazaguanine (preQ(1)). The assay is based on the ability of the preQ(1) aptamer to fold, upon ligand binding, into a pseudoknotted structure that is capable of stimulating -1 ribosomal frameshifting (-1 FS). Aptamers from three different species were found to induce between 7% and 20% of -1 FS in response to increasing preQ(1) levels, whereas preQ(1) analogues were 100-1000-fold less efficient. In depth mutational analysis of the Fusobacterium nucleatum aptamer recapitulates most of the structural details previously identified for preQ(1) aptamers from other bacteria by crystallography and/or NMR spectroscopy. In addition to providing insight into the role of individual nucleotides of the preQ(1) riboswitch aptamer in ligand binding, the presented system provides a valuable tool to screen small molecules against bacterial riboswitches in a eukaryotic background.
authors: Department of Molecular Genetics, Leiden Institute of Chemistry, Leiden University, PO Box 9502, Leiden, The Netherlands.
authors: Chien-Hung
authors: CH
authors: Yu
authors: Jinghui
authors: J
authors: Luo
authors: Dirk
authors: D
authors: Iwata-Reuyl
authors: René C L
authors: RC
authors: Olsthoorn
mesh_terms: D052157:Aptamers, Nucleotide; D001483:Base Sequence; D018965:Frameshifting, Ribosomal; D009690:Nucleic Acid Conformation; D058928:Riboswitch
chemical_list: D052157:Aptamers, Nucleotide; D058928:Riboswitch