Altered mRNA cap recognition activity of initiation factor 4E in the yeast cell cycle division mutant cdc33

Abstract

The mutation in the S. cerevisiae cell cycle division mutant cdc33 consists of a single G to A transition in the open reading frame encoding translation initiation factor 4E (eIF-4E). This leads to the substitution of glycine 113 by aspartic acid close to tryptophane 115 in the protein. This mutation reduces cap binding activity of eIF-4E as measured by binding of eIF-4E to m7GDP agarose columns and slows down overall protein synthesis at the non-permissive temperature. Comparison of the cdc33 mutation with other mutations affecting eIF-4E function supports the view that tryptophane residues and their flanking regions are involved in cap binding activity of eIF-4E.