Translational activities of EF-Tu [G222D] which cannot be reconciled with the classical scheme of the polypeptide chain elongation cycle.

We have developed a cell-free system of E. coli that enables us to study the in vitro translation of natural mRNA mediated by wild-type or mutant EF-Tu. Various mutant EF-Tu species have been analyzed, one of which, EF-Tu [G222D], appeared to be virtually unable to mediate the translation of natural mRNA. Since this mutant factor is able to participate in translation in vivo by suppressing nonsense and frameshift mutations in cooperation with EF-Tu [A375T], a revision of the generally accepted scheme of the elongation cycle has been proposed (Bosch, L., Vijgenboom, E., & Zeef, L.A.H., 1996, Biochemistry 36).