The elongation factor 1 from wheat germ: structural and functional properties.

Three forms of elongation factor 1 (EF1A, EF1B and EF1C) were isolated from wheat germ; the preparation obtained by successive chromatography on DEAE-Sephadex A-50, hydroxylapatite and Sephadex G-200 showed about 90% purity. The molecular masses of these forms were about: 61 000, 48 000 and 12 500, respectively. EF1A was the only form which formed the ternary complex GTP-EF1-AA-tRNA and was the most active in binding of Phe-tRNA to the poly-U programmed ribosomes. Based on the data of amino acid analysis, N-terminal amino acid determination and previously described proteolysis (Pulikowska et al., Biochem. Biophys. Res. Commun., 1979, 91, 1011-1017), it is assumed that EF1C is a basic structural subunit of elongation factor EF1 from wheat germ, but only EF1A shows the conformation-dependent full biological activity.