ISOLATION AND CHARACTERIZATION OF THE DROSOPHILA-MELANOGASTER GENE ENCODING TRANSLATION-INITIATION FACTOR EIF-2-BETA

Drosophila melanogaster cDNA clones encoding the P subunit of translat ion initiation factor 2 (eIF-2) were isolated and sequenced. The longe st cDNA predicts a protein of 312 amino acids (aa), which possesses a putative RNA-binding motif and a highly charged N-terminal region comp osed of three basic polylysine blocks. The aa sequence comparison of D . melanogaster eIF-2 beta with its human and yeast counterparts demons trates a high degree of similarity, especially within the C-terminal r egion. Northern analysis indicates quasi-constitutive expression of eI F-2 beta throughout D. melanogaster development.