Eukaryotic acidic phosphoproteins interact with the ribosome through their amino-terminal domain.

Variable-size fragments of the four yeast acidic ribosomal protein genes rpYP1 alpha, rpYP1 beta, rpYP2 alpha and rpYP2 beta were fused to the LacZ gene in the vector series YEp356-358. The constructs were used to transform wild-type Saccharomyces cerevisiae and several gene-disrupted strains lacking different acidic ribosomal protein genes. The distribution of the chimeric proteins between the cytoplasm and the ribosomes, tested as beta-galactosidase activity, was estimated.

[Use of gene fusion in the study of the interaction of ribosomal protein L45 with the Saccharomyces cerevisiae ribosome].

Cytoplasmic ribosomes from all cells have a set of highly acidic proteins (proteins A; pI less than 4.0). Proteins A are indispensable for ribosomal function since they mediate the interaction between GTP dependent translational factors and the ribosome.