We quantified the effect of Mg2+ on thiamine pyrophosphate (TPP) binding to TPP-dependent thiA riboswitch RNA. The association constant of TPP binding to the riboswitch at 20°C increased from 1.2 × 106 to 50 × 106 M-1 as the Mg2+ concentration increased from 0 to 1 mM. Furthermore, circular dichroic spectra under various conditions showed that 1 mM Mg2+ induced a local structural change of the riboswitch, which might be pivotal for TPP binding. These results indicate that a physiological concentration of Mg2+ can regulate TPP binding to the thiA riboswitch. © 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Yamauchi, T., Miyoshi, D., Kubodera, T., Nishimura, A., Nakai, S., & Sugimoto, N. (2005). Roles of Mg2+ in TPP-dependent riboswitch. FEBS Letters, 579(12), 2583–2588. https://doi.org/10.1016/j.febslet.2005.03.074