Elongation factor 1 contains two homologous guanine-nucleotide exchange proteins as shown from the molecular cloning of beta and delta subunits.
1993
Cormier, Patrick | Osborne, Howard Beverley | Morales, Julia | Bassez, Therese | Minella, Odile | Poulhe, Robert | Bellé, Robert | Mulner-Lorillon, O.
Elongation factor 1 mediates the elongation step of mRNA translation. The transfer of aminoacyl-tRNA to ribosomes under hydrolysis of GTP is catalyzed by a GTP binding protein, EF1Ia. A guanine-nucleotide exchange complex now referred as EF1beta gamma delta replaces GDP by GTP on EF1alpha (1). A complex, purified from Xenopus oocytes as a substrate for the meiotic and mitotic p34Cdc2 kinase, was shown to contain the guanine-nucleotide exchange activity (2). The Xenopus complex is composed of three main proteins, p30, p36 and p47. Surprisingly, microsequencing of two of its components, p36 and p30 suggested the presence of two related proteins (2). We have previously cloned and sequenced the cDNA encoding for p47 or EF1gamma (3) and p36 or EF1delta (4), we present here the molecular cloning of p30 or EF1beta. This result allows for the first time, sequence analysis of EF1beta and delta proteins, both present in the same complex.
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