Characterisation of a cDNA encoding chick eukaryotic translation initiation factor-2 beta

A full length cDNA for the beta subunit of chick (Gallus gallus) eukaryotic translation initiation factor-2 is described. This cDNA was isolated by sc reening a chick cDNA library with a probe derived via differential display of developing chick heart tissue. Up-regulated expression of eIF-2 beta mRN A was confirmed by reverse Northern dot blot analysis. eIF-2 beta, together with eIF-2 alpha and eIF-2 gamma, comprise subunits of a complex that prom otes the binding of methionyl-tRNA to ribosomes during the initiation of pr otein translation. The nucleotide sequence of the chick eIF-2 beta cDNA pre dicts a protein of 334 amino acids that has 95%, 93%, 56% and 37% sequence identity with rabbit, human, drosophila and yeast eIF-2 beta, respectively. The deduced eIF-2 beta protein contains a number of functional motifs and domains consistent with the putative function of this protein; these includ e a potential C-2-C-2 zinc-finger binding domain, three polylysine regions, and three acidic regions.