Christopher S. Francklyn is in the Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405, USA.franck@emba.uvm.edu
A structure of the complex of tRNAGlu and class I glutamyl-tRNA synthetase from Thermus thermophilus provides new details of tRNA recognition, and an accompanying mutational study provides a model for how a discriminating enzyme could have evolved from a less discriminating predecessor.
