Recovery of polysome function of T4-infected Escherichia coli after brief treatment with chloramphenicol and rifampin.

T4-infected Escherichia coli cells briefly exposed to rifampin, or to rifampin plus chloramphenicol, were capable of protein synthesis for some time after removal of the antibiotics, although ribonucleic acid synthesis was irreversibly inhibited. Partially completed peptides trapped on polysomes by high levels of chloramphenicol were eventually completed after removal of the drug, as demonstrated by subjecting labeled peptides from appropriate polysome regions to polyacrylamide disc gel electrophoresis. Thus, the effect of the drug appears to be reversible on the molecular as well as the cellular level.