Coordination environment of a site-bound metal ion in the hammerhead ribozyme determined by 15N and 2H ESEEM spectroscopy.

ABSTRACT: Although site-bound Mg2+ ions have been proposed to influence RNA structure and function, establishing the molecular properties of such sites has been challenging due largely to the unique electrostatic properties of the RNA biopolymer. We have previously determined that, in solution, the hammerhead ribozyme (a self-cleaving RNA) has a high-affinity metal ion binding site characterized by a K(d,app) < 10 microM for Mn2+ in 1 M NaCl and speculated that this site has functional importance in the ribozyme cleavage reaction. Here we determine both the precise location and the hydration level of Mn2+ in this site using ESEEM (electron spin-echo envelope modulation) spectroscopy. Definitive assignment of the high-affinity site to the activity-sensitive A9/G10.1 region is achieved by site-specifi

SUBMITTER: Vogt M 

PROVIDER: S-EPMC3217337 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature