An RNase that has 5'-3' exonuclease and possibly endonuclease activity. Plays a role in 16S and 23S rRNA processing. Might have a role in mRNA maturation and/or decay. Binds up to 2 Zn(2+) ions per subunit. It is not clear if Zn(2+) or Mg(2+) is physiologically important. Homodimer, may be a subunit of the RNA degradosome. Not essential. Loss of 5'-processing of pre-5.8S rRNA, and the 2.6 kb rRNA which form the two 23S rRNA fragments. No removal of last 3 nucleotides at the 5' end during processing of 16S rRNA. Belongs to the metallo-beta-lactamase superfamily. RNA-metabolizing metallo-beta-lactamase-like family. Bacterial RNase J subfamily.