Thermodynamics of RNA hairpins containing single internal mismatches.

AUTOR(ES)

Meroueh, M

RESUMO

Thermodynamic parameters and circular dichroism spectra are presented for RNA hairpins containing single internal mismatches in the stem regions. Three different sequence contexts for the G*U mismatch and two contexts for C*A, G*A, U*U, A*C and U*G mismatches were examined and compared with Watson-Crick base-pair stabilities. The RNA hairpins employed were a microhelix and tetraloop representing the Escherichia coli tRNAAlaacceptor stem and sequence variants that have been altered at the naturally occurring G*U mismatch site. UV melting studies were carried out under different conditions to evaluate the effects of sodium ion concentration and pH on the stability of mismatch-containing hairpins. Our main findings are that single internal mismatches exhibit a range of effects on hairpin stability. In these studies, the size and sequence of the loop and stem are shown to influence the overall stability of the RNA, and have a minor effect on the relative mismatch stabilities. The relationship of these results to RNA-ligand interactions involving mismatch base-pairs is discussed.

Documentos Relacionados

• NMR solution structure of a DNA dodecamer containing single G.T mismatches.
• Thermodynamics of internal C.T mismatches in DNA.
• The crystal structure of an RNA oligomer incorporating tandem adenosine-inosine mismatches.
• A human 200-kDa protein binds selectively to DNA fragments containing G.T mismatches.
• DNA mismatch repair in Xenopus egg extracts: repair efficiency and DNA repair synthesis for all single base-pair mismatches.