Ribosomal abnormality in recA mutants of Escherichia coli.

The tif-1 mutation has been shown to affect protein synthesis in vitro by increasing translational ambiguity (Ephrati-Elizur, Luther-Davies and Hayes, 1976). It is demonstrated here that some recA mutations confer similar abnormality. By comparing suitable combinations of ribosomes and soluble proteins from recA+ and recA cells the defect is shown to be associated with ribosomes. The recA mutation, which suppresses most phenotype characteristics of the tif-1 mutation (Castellazzi, George and Buttin, 1972(b)) does not suppress the ribosomal abnormality. Since the closely linked tif-1 and recA mutations lead to the expression of a common property they may be in the same gene.