Structure of the cytosine-cytosine mismatch in the thymidylate synthase mRNA binding site and analysis of its interaction with the aminoglycoside paromomycin.

ABSTRACT: The structure of a cytosine-cytosine (CC) mismatch-containing RNA molecule derived from a hairpin structure in the thymidylate synthase mRNA that binds the aminoglycoside paromomycin with high affinity was determined using nuclear magnetic resonance (NMR) spectroscopy. The cytosines in the mismatch form a noncanonical base pair where both cytosines are uncharged and stack within the stem of the RNA structure. Binding to paromomycin was analyzed using isothermal titration calorimetry (ITC) to demonstrate the necessity of the CC mismatch and to determine the affinity dissociation constant of this RNA to paromomycin to be 0.5 +/- 0.3 microM. The CC mismatch, and the neighboring GC base pairs experienced the highest degree of chemical shift changes in their H6 and H5 resonances indicating that

SUBMITTER: Tavares TJ 

PROVIDER: S-EPMC2673063 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature