Conformational peculiarities of rRNA inff supMet from E. coli as revealed by fluorescent methods

Abstract

Conformational transitions in several individual tRNAs (tRNAMetf, tRNAPhe from E. coli, tRNAVal1, tRNASer, tRNAPhe from yeast) have been studied under various environmental conditions. The binding isotherms studies for dyes-tRNA complexes exhibited similarities in conformational states of all tRNAs investigated at low ionic strength (0.01 M NaCl). By contrast, at high ionic strength (0.4 M NaCl or 2 X 10(-4) M Mg2+) a marked difference is found in structural features of tRNAMetf as compared with other tRNAs used. The tRNAMetf is the only tRNA species that does not reveal the strong type of complexes with ethidium bromide, acriflavine and acridine orange.

Ethidium bromide binding to transfer RNA: transfer RNA as a model system for studying drug-RNA interactions

“…This indicates that EB can bind at different sites on different tRNAs. Binding of EB to E. coli tRNAfMet is somewhat different than other tRNAs as suggested on the basis of optical results (Surovaya and Borissova, 1976). The NMR results on E. coli tRNAfMel are not consistent with a unique intercalation site and suggest that there are either several intercalation sites or outside binding sites or both.…”