RNase J is involved in the 5′-end maturation of 16S rRNA and 23S rRNA in Sinorhizobium meliloti

Sinorhizobium meliloti harbours genes encoding orthologs of ribonuclease (RNase) E and RNase J, the principle endoribonucleases in Escherichia coli and Bacillus subtilis, respectively. To analyse the role of RNase J in S. meliloti, RNA from a mutant with miniTn5-insertion in the RNase J-encoding gene was compared to the wild-type and a difference in the length of the 5.8S-like ribosomal RNA (rRNA) was observed. Complementation of the mutant, Northern blotting and primer extension revealed that RNase J is necessary for the 5′-end maturation of 16S rRNA and of the two 23S rRNA fragments, but not of 5S rRNA.