Influence of Mg²⁺ on the conformational flexibility of a tetracycline aptamer.

ABSTRACT: The tetracycline-binding RNA aptamer (TC-aptamer) is a synthetic riboswitch that binds the antibiotic tetracycline (TC) with exceptionally high affinity. Although a crystal structure exists of the TC-bound state, little is known about the conformational dynamics and changes upon ligand binding. In this study, pulsed electron paramagnetic resonance techniques for measuring distances (PELDOR) in combination with rigid nitroxide spin labels (Çm spin label) were used to investigate the conformational flexibility of the TC-aptamer in the presence and absence of TC at different Mg²⁺ concentrations. TC was found to be the essential factor for stabilizing the tertiary structure at intermediate Mg²⁺ concentrations. At higher Mg²⁺ concentrations, Mg²⁺ alon

SUBMITTER: Hetzke T 

PROVIDER: S-EPMC6298572 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature