EVIDENCE FOR THE FORMATION OF AN UNUSUAL TERNARY COMPLEX OF RABBIT LIVER EF-1-ALPHA WITH GDP AND DEACYLATED TRANSFER-RNA

Eukaryotic translation elongation factor 1 alpha is known to interact in GTP-bound form with aminoacyl-tRNA promoting its binding to the rib osome, In this paper another ternary complex [EF-1 alphaGDP*deacylate d tRNA], never considered in widely accepted elongation schemes, is re ported for the first time, The formation of this unusual complex, post ulated earlier (FEBS Lett. (1996) 382, 18-20), has been detected by fo ur independent methods, [EF-1 alphaGDP]-interacting sites are located in the acceptor stem, T psi C stem and T psi C loop of tRNA(Phe) and tRNA(Leu) molecules, Both tRNA and EF-1 alpha are found to undergo cer tain conformational changes during their interaction, The ability of E F-1 alpha to form a complex with deacylated tRNA indicates that the fa ctor may perform an important role in tRNA and aminoacyl-tRNA channeli ng in higher cukaryotic cells. (C) 1997 Federation of European Biochem ical Societies.