Observation of preQ 1 -II riboswitch dynamics using single-molecule FRET.

Autor: Warnasooriya C; a Department of Biochemistry & Biophysics and Center for RNA Biology, School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA., Ling C; a Department of Biochemistry & Biophysics and Center for RNA Biology, School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA., Belashov IA; a Department of Biochemistry & Biophysics and Center for RNA Biology, School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA., Salim M; a Department of Biochemistry & Biophysics and Center for RNA Biology, School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA., Wedekind JE; a Department of Biochemistry & Biophysics and Center for RNA Biology, School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA., Ermolenko DN; a Department of Biochemistry & Biophysics and Center for RNA Biology, School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA.
Jazyk: angličtina
Zdroj: RNA biology [RNA Biol] 2019 Sep; Vol. 16 (9), pp. 1086-1092. Date of Electronic Publication: 2018 Oct 30.
DOI: 10.1080/15476286.2018.1536591
Abstrakt: PreQ 1 riboswitches regulate the synthesis of the hypermodified tRNA base queuosine by sensing the pyrrolopyrimidine metabolite preQ 1 . Here, we use single-molecule FRET to interrogate the structural dynamics of apo and preQ 1 -bound states of the preQ 1 -II riboswitch from Lactobacillus rhamnosus . We find that the apo-form of the riboswitch spontaneously samples multiple conformations. Magnesium ions and preQ 1  stabilize conformations that sequester the ribosome-binding site of the mRNA within the pseudoknotted structure, thus inhibiting translation initiation. Our results reveal that folding of the preQ 1 -II riboswitch is complex and provide evidence favoring a conformational selection model of effector binding by riboswitches of this class.
Databáze: MEDLINE
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