mutant species of eftu altered at position 375 exhibit a reduced affinity for aminoacylated transferrnas the interaction between eftu x gtp and aminoacyltrna is shown to be influenced by mutations at site 375 of this threedomain protein site 375 is located in domain ii near the interface with domain i 1984 embo j 3 113120 replacement of the alanine at this site by a threonine or valine residue results in lower binding constants with phetrna and tyrtrna as was evaluated by the hydrolysis protection technique the data are discussed in the light of what is known about the threedimensional structure of the protein and its interaction sites with aminoacyltrna