NMR studies of the structure and Mg2+ binding properties of a conserved RNA motif of EMCV picornavirus IRES element.

ABSTRACT: The structure and Mg(2+) binding properties of a conserved 75mer RNA motif of the internal ribosome entry site (IRES) element of encephalomyocarditis virus picornavirus have been investigated by (1)H-NMR and UV melting experiments. The assignment of the imino proton resonances with characteristic chemical shift dispersion for canonical and non-canonical base pairs confirmed the predicted secondary structure of the 75mer and its fragments. Addition of Mg(2+) resulted in a dramatic increase in apparent melting temperature, with the 75mer RNA registering the biggest increase, from 63 to 80 degrees C, thus providing evidence for enhanced stability arising from Mg(2+) binding. Similarly, addition of Mg(2+) induced selective changes to the chemical shifts of the imino protons of a GCGA tetraloop

SUBMITTER: Phelan M 

PROVIDER: S-EPMC519103 | biostudies-literature | 2004

REPOSITORIES: biostudies-literature