title: Glycols modulate terminator stem stability and ligand-dependency of a glycine riboswitch.
abstract: The Bacillus subtilis glycine riboswitch comprises tandem glycine-binding aptamers and a putative terminator stem followed by the gcvT operon. Gene expression is regulated via the sensing of glycine. However, we found that the riboswitch behaves in a "glycine-independent" manner in the presence of polyethylene glycol (PEG) and ethylene glycol. The effect is related to the formation of a terminator stem within the expression platform under such conditions. The results revealed that increasing PEG stabilized the structure of the terminator stem. By contrast, the addition of ethylene glycol destabilized the terminator stem. PEG and ethylene glycol have opposite effects on transcription as well as on stable terminator stem formation. The glycine-independency of the riboswitch and the effects of such glycols might shed light on the evolution of riboswitches.
authors.affiliation: Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
authors.forename: Kokoro
authors.initials: K
authors.lastname: Hamachi
authors.forename: Hikari
authors.initials: H
authors.lastname: Hayashi
authors.forename: Miyuki
authors.initials: M
authors.lastname: Shimamura
authors.forename: Yuiha
authors.initials: Y
authors.lastname: Yamaji
authors.forename: Ai
authors.initials: A
authors.lastname: Kaneko
authors.forename: Aruma
authors.initials: A
authors.lastname: Fujisawa
authors.forename: Takuya
authors.initials: T
authors.lastname: Umehara
authors.forename: Koji
authors.initials: K
authors.lastname: Tamura
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D020029:Base Pairing; D001483:Base Sequence; D024202:Electrophoretic Mobility Shift Assay; D019855:Ethylene Glycol / Q000494:pharmacology; D019143:Evolution, Molecular; D031541:Fluorescence Resonance Energy Transfer; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D005998:Glycine / Q000378:metabolism*; D006018:Glycols / Q000378:metabolism*; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011092:Polyethylene Glycols / Q000494:pharmacology; D058928:Riboswitch / Q000187:drug effects / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013728:Terminator Regions, Genetic / Q000187:drug effects / Q000235:genetics
chemical_list: D006018:Glycols; D009841:Oligonucleotides; D058928:Riboswitch; D011092:Polyethylene Glycols; D019855:Ethylene Glycol; D005998:Glycine
keywords: Ethylene glycol; Glycine riboswitch; PEG; Stability; Terminator stem