Open AccessTertiary Structure of tRNAs in Solution Monitored by Phosphodiester Modification with Ethylnitrosourea
Author(s) -
VLASSOV Valentin V.,
GIEGÉ Richard,
EBEL JeanPierre
Publication year - 1981
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1981.tb05575.x
Subject(s) - phosphodiester bond , alkylation , chemistry , transfer rna , ethidium bromide , yeast , stereochemistry , denaturation (fissile materials) , phosphate , guanidinium chloride , escherichia coli , biochemistry , crystallography , rna , dna , enzyme , nuclear chemistry , gene , catalysis
The alkylation by ethylnitrosourea of phosphodiester bonds in yeast tRNA Phe , tRNA Val and in Escherichia coli tRNA Glu , tRNA Met f , tRNA met m and tRNA Phe was investigated under various conditions. In unfolded tRNAs the reactivities of phosphates in various positions toward the reagent were similar. In the folded tRNAs remarkable differences in reactivities of phosphates located in various positions of the molecules were observed. In yeast and E. coli tRNA Phe , reactivities of phosphates in positions 9, 10, 11, 19, 49, 58, 59 and 60 were found to be strongly decreased. Some decrease in reactivity was observed for phosphates 23 and 24. Spermine and ethidium bromide did not influence the pattern of phosphate alkylation in the TΨC arm of yeast tRNA Phe . Our solution results fit with the crystal structure of tRNA Phe with respect to the potential availability of the phosphates in this tRNA to solvent as shown by others. Judging from the pattern of phosphate reactivities, the structure of E. coli tRNA Phe is very similar to that of yeast tRNA Phe . Upon thermal denaturation of the yeast tRNA Phe , the reactivity of the low‐reactive phosphates increased, demonstrating a cooperative melting curve. A comparison of the pattern of phosphate alkylation in several tRNAs, essentially in their TΨC arms, revealed a striking similarity, suggesting that the folding of these tRNAs is essentially similar.