Occurrence of four subunits in high molecular weight forms of polypeptide chain elongation factor 1 from wheat embryo

In contrast to high molecular weight forms of elongation factor 1 (EF-1H) from animal sources which contain three subunits, EF-1a, EF-1b, and EF-1c, EF-1H from wheat embryo consisted of four subunits, EF-1a, EF-1b, EF-1b', and EF-1c, in an equimolar ratio. The molecular weights of EF-1a, EF-1b, EF-1b', and EF-1c from wheat embryo were 52,000, 29,000, 28,000, and 48,000, respectively. In the animal system, EF-1a and EF-1b correspond functionally to EF-Tu and EF-Ts, respectively. In the wheat system, however, both EF-1b and EF-1b' had the EF-Ts-like activity to stimulate EF-1a-dependent binding of aminoacyl-tRNA to ribosomes. EF-1b and EF-1b' from wheat embryo gave 21 and 20 tryptic peptides, respectively. Twenty peptides were common.