Saccharomyces cerevisiae was selected as a model system due to its potential industrial interest. In this organism there are 3 acidic proteins present in the ribosome. The proteins were purified and polyclonal and monoclonal antibodies specific for each polypeptide were prepared. The genes encoding ribosomal proteins L44, L45 and L44' were cloned and strains lacking each one of the genes were obtained subsequently using gene disruption techniques. The defective strains were viable.
The results have shown that the different acidic ribosomal proteins seem to play a similar role and can be substituted functionally among themselves.