Quoi?
"In order to study how Escherichia coli leucyl-tRNA synthetase recognizes tRNALeu and discriminates it from the other two class II tRNAs, tRNASer and tRNATyr, various mutations were introduced into class II tRNA transcripts. The discriminator base A73, but not the anticodon sequence, was found to serve as a critical recognition element of tRNALeu."
Asahara et al, J Mol Biol 1993
https://www.sciencedirect.com/science/article/abs/pii/S0022283683712775