Conformational peculiarities of tRNAMetf from E. coli as revealed by fluorescent methods

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.