Removal of Y-37 from tRNA_yeast^phe alters oligomer binding to two loops

The association constants of complementary oligomers were used to monitor changes in the structure of tRNA_yeast^phe as a consequence of excision of a single base Y in the anticodon loop and of clipping the molecule at the point of excision. Significant changes were found not only in the binding constants of oligomers complementary to the anticodon loop but also in the K of an oligomer complementary to the dihydro U loop. The results suggest that either a single base change in a tRNA may alter structure elsewhere in the molecule or that the acid treatment necessary to remove Y irreversibly alters the structure of tRNA_yeast^phe.