Binding of Complementary Oligonucleotides to Free and Aminoacyl Transfer Ribonucleic Acid Synthetase Bound Transfer Ribonucleic Acid

Complementary oligonucleotides have been tested for their ability to hybridize to various sequences on tRNAIle from Escherichia coli B. Strong binding is observed of complementary oligomers to the anticodon section and to the ACC sequence at the 3′ terminus. Strong binding of complementary oligomers to the dihydrouridine loop does not occur, possibly because of limitations placed by the three dihydrouridine residues in this loop. When tRNA^Ile is complexed with the isoleucyl-tRNA synthetase, oligomers cannot be hybridized to either the anticodon section or to the ACC sequence at the 3′ terminus. This suggests that both the anticodon region and the 3′ terminus are covered or shielded in some way by the enzyme and, therefore, that the synthetase-tRNA interaction may encompass regions which are quite far apart in thetRNA.