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

Conformational transitions in several individual tRNAs (tRNA _inff ^supMet , tRNA^Phe from E. coli, tRNA _inf1 ^supVal , tRNA^Ser, tRNA^Phe 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 2×10^-4 M Mg²⁺) a marked difference is found in structural features of tRNA _inff ^supMet as compared with other tRNAs used. The tRNA _inff ^supMet is the only tRNA species that does not reveal the strong type of complexes with ethidium bromide, acriflavine and acridine orange.