RESTORATION OF VALINE ACCEPTOR ACTIVITY BY COMBINING OLIGONUCLEOTIDE FRAGMENTS DERIVED FROM A BACILLUS SUBTILIS RIBONUCLEASE DIGEST OF ESCHERICHIA COLI VALINE TRANSFER RNA

Valine tRNA from Escherichia coli, treated with Bacillus subtilis ribonuclease in the presence of Mg2+ yielded two large fragments. They contained the -C-C-A end and the pGp end, respectively, and could be separated from each other by means of DEAE-cellulose column chromatography followed by rechromatography with DEAE-Sephadex A-25 at pH 2.7. When the two fragments were combined and renatured in the presence of Mg2+, valine acceptor activity was fully restored. It is essential to combine the two fragments for the reactivation of valine acceptor activity. No acceptor activity was restored with either component alone. The restoration of valine acceptor activity was temperature and time dependent, and the presence of divalent ion such as Mg2+ was also necessary. The thermal denaturation of the ribonuclease-treated valine tRNA occurred at quite a lower temperature than that of native valine tRNA. From the data of thermal denaturation profile of the two fragments and their reconstituted molecule, a possible mechanism for the renaturation process will be discussed. © 1969.