Ribosome degradation in Escherichia coli induced by colicin E2

The mode of action of colicin E₂ on ribosomes in $\text{Escherichia coli}$ cells was investigated by zonal centrifugation analysis. Ribosome particles, both 50S and 30S, were degraded to smaller contents with the lapse of time by the action of colicin E₂. Gradual reduction of S values of each particles could not be observed and degradative intermediates of possible RNA-protein complex were detected only at the position between 30S and 4S in the zonal centrifugation profile, which indicated the destruction of ribosome in burst-out attitude. 50S ribosome fraction influenced by colicin E₂ contained both 23S and half-sized RNA. From these data, the mode of action of colicin E₂ on ribosomes in $\text{E. coli}$ was discussed.