Suppressors suaC109 and suaA101 of Aspergillus nidulans alter the ribosomal phenotype in vitro.

A new homologous, cell-free system for protein synthesis has been devised for use with ribosomes and elongation factors from Aspergillus nidulans. Ribosome preparations from strains with either the suaA101 or suaC109 mutations have a higher misreading ratio (non-cognate:cognate amino acid incorporation) in the presence of hygromycin than controls. They can be classed as fidelity mutants. These results also prove that the mutations must be in genes coding for ribosomal proteins or enzymes which modify ribosomal proteins post-translationally. Alternatively, the genes could code for translation factors.