Evidence for the formation of an unusual ternary complex of rabbit liver EF-1 alpha with GDP and deacylated tRNA

Eukaryotic translation elongation factor 1 alpha is known to interact in GTP-bound form with aminoacyl-tRNA promoting its binding to the ribosome, In this paper another ternary complex [EF-1 alpha*GDP*deacylated tRNA], never considered in widely accepted elongation schemes, is reported for the first time, The formation of this unusual complex, postulated earlier (FEBS Lett. (1996) 382, 18-20), has been detected by four independent methods, [EF-1 alpha*GDP]-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 certain conformational changes during their interaction, The ability of EF-1 alpha to form a complex with deacylated tRNA indicates that the factor may perform an important role in tRNA and aminoacyl-tRNA channeling in higher cukaryotic cells. (C) 1997 Federation of European Biochemical Societies.