Chemical modification of tRNA yeastTyr with bisulfite. A new method to modify isopentenyladenosine residue

Abstract

When tRNA yeast Tyr was treated with bisulfite at pH 7, the uracil (U) residue next to the 5′-end of the anticodon and the isopentenyladenine (iA) residue adjacent to the 3′-end of it were chemically modified. On treatment of this transformed tRNA with weak alkali, the modified U residue regenerated U, while the modified iA remained unaltered. The modification of both the U and iA residues did not affect the amino acid accepting activity of the tyrosine tRNA, while the specific modification of the iA residue resulted in the decrease of the ability of the tyrosyl tRNA to bind to the messenger-ribosome complex.