Conformation and mechanical property of rpoS mRNA inhibitory stem studied by optical tweezers and X-ray scattering.

ABSTRACT: 3' downstream inhibitory stem plays a crucial role in locking rpoS mRNA 5' untranslated region in a self-inhibitory state. Here, we used optical tweezers to study the unfolding/refolding of rpoS inhibitory stem in the absence and presence of Mg2+. We found adding Mg2+ decreased the free energy of the RNA junction without re-arranging its secondary structure, through confirming that this RNA formed a canonical RNA three-way junction. We suspected increased free energy might change the relative orientation of different stems of rpoS and confirmed this by small angle X-ray scattering. Such changed conformation may improve Hfq-bridged annealing between sRNA and rpoS RNA inhibitory stem. We established a convenient route to analyze the changes of RNA conformation and folding dynamics by combini

SUBMITTER: Hu X 

PROVIDER: S-EPMC6762075 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature