The site of interaction of aminoacyl‐tRNA with elongation factor Tu

We have used RNases T1, T2 and A to digest two aminoacyl‐tRNAs, Escherichia coli Phe‐tRNAPhe and E. coli Met‐ tRNAMetm both in the naked forms and in ternary complexes with E. coli elongation factor Tu (EF‐Tu) and GTP. An analysis of the ‘footprinting’ results has led to an interpretation that has localized the part of the three‐dimensional structure of aminoacyl‐tRNA covered by the protein in the ternary complex. In terms of the three‐dimensional structure of tRNA established for yeast tRNAPhe, EF‐Tu covers the aa‐end, aa‐stem, T‐stem, and extra loop on the side of the L‐shaped tRNA that exposes the extra loop.