Modification of Escherichia coli glutamate transfer ribonucleic acid with bisulfite.

摘要: Abstract Bisulfite (2 m, pH 6, 20°) converted 6 of the 27 cytidine residues in Escherichia coli glutamate transfer RNA to uridine within 24 hours; no more were modified following 72 hours. Radioactive bisulfite and chromatographic analysis T1 ribonuclease digest showed that each reacted completion. Five 21 nonreactive cytidines are non-hydrogen-bonded sections tRNA "cloverleaf" arrangement, leading conclusion these not as exposed this arrangement might, a priori, indicate, but buried three-dimensional structure existing modification medium. The (six uridines) had diminished melting temperatures, an increased hyperchromicity, decreased retention volue on gel columns, indicating conformational changes. It also acceptance activity under normal assay conditions, probably result changes conformation observed.