The heavy form of elongation factor 1 in [formula omitted] embryos is functionally analogous to a complex of bacterial factors EF-Tu and EF-Ts

Abstract

The purified heavy form of elongation factor 1 (EF-1) from cysts of Artemia salina was found to catalyze the exchange of free GTP with a complex of EF-1 L (EF-1 α) and GDP. Furthermore, after heat treatment of EF-1 H in the presence of GTP, the factor, while inactive by itself, stimulated aminoacyl-tRNA binding to ribosomes as well as polyphenylalanine synthesis when combined with EF-1 α. These functional properties are similar to those reported recently for purified EF-1 β from pig liver [ Nagata,S., Motoyoshi,K., and Iwasaki,K. (1976) Biochem. Biophys. Res. Comm. 71 , 933–938 ]. We suggest that Artemia EF-1 H consists of a EF-1 α. EF-1 β complex which is functionally analogous to bacterial EF-Tu · EF-Ts.