Linking folding dynamics and function of SAM/SAH riboswitches at the single molecule level.

ABSTRACT: Riboswitches are regulatory elements found in bacterial mRNAs that control downstream gene expression through ligand-induced conformational changes. Here, we used single-molecule FRET to map the conformational landscape of the translational SAM/SAH riboswitch and probe how co-transcriptional ligand-induced conformational changes affect its translation regulation function. Riboswitch folding is highly heterogeneous, suggesting a rugged conformational landscape that allows for sampling of the ligand-bound conformation even in the absence of ligand. The addition of ligand shifts the landscape, favoring the ligand-bound conformation. Mutation studies identified a key structural element, the pseudoknot helix, that is crucial for determining ligand-free conformations and their ligand responsiven

SUBMITTER: Liao TW 

PROVIDER: S-EPMC10516623 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature