The rne gene and ribonuclease E

The cloned rne + gene complements temperature sensitive RNase E mutations and directs the synthesis of a polypeptide. In vitro the RNA transcribed from the rne gene directs the synthesis of a number of polypeptides, one of which is identical in size to the in vivo product of the rne gene. A rabbit reticulocyte cell free extract programmed with this RNA produced RNase E activity. Thus, it is evident that the rne gene is the structural gene for RNase E. However, the in vivo product of the cloned RNase E gene is more thermolabile than the chromosomal gene product. When cells containing the rne plasmid were treated with chloramphenicol, the pre-existing RNase E became less heat labile with time. This leads to the suggestion that in the cell RNase E undergoes post-translational modification(s).