Sequence Studies on the α-, β-, and γ-Chains of Elongation Factor 1 from Artemia : Some Practical Notes

Abstract

In eukaryotic organisms, elongation factor 1 encloses three polypeptide chains, designated as EF-1α, EF-1s and EF-1γ. EF-1α, a 51,000 MW protein, is the eukaryotic equivalent of the prokaryotic, aminoacyl tRNA-carrying enzyme EF-Tu. Both EF-1 α and EF-Tu can bind aminoacyl tRNA and GDP or GTP. EF-1 β, having a MW of 26,000, corresponds to prokaryotic EF-Ts, the enzyme that exchanges in the EF-Tu. GDP-complex, GDP for GTP. The function of EF-1γ, which has no prokaryotic counterpart, is still unknown. This protein, which has a MW of 46,000, is normally tightly associated with the s-chain, forming the complex EF-1 βγ. In the brine shrimp Artemia, a high molecular weight complex between the three polypeptide chains can be isolated from dormant cysts; in the free-swimming nauplii, however, free EF-1α is found predominantly. The significance of the complexing of EF-1 α with the other two chains in dormant cysts is still unclear (for a recent review see [1]).