Unprecedented tunability of riboswitch structure and regulatory function by sub-millimolar variations in physiological Mg2.

ABSTRACT: Riboswitches are cis-acting regulatory RNA biosensors that rival the efficiency of those found in proteins. At the heart of their regulatory function is the formation of a highly specific aptamer-ligand complex. Understanding how these RNAs recognize the ligand to regulate gene expression at physiological concentrations of Mg2+ ions and ligand is critical given their broad impact on bacterial gene expression and their potential as antibiotic targets. In this work, we used single-molecule FRET and biochemical techniques to demonstrate that Mg2+ ions act as fine-tuning elements of the amino acid-sensing lysC aptamer's ligand-free structure in the mesophile Bacillus subtilis. Mg2+ interactions with the aptamer produce encounter complexes with strikingly different sensitivities to the ligand i

SUBMITTER: McCluskey K 

PROVIDER: S-EPMC6614840 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature