Endoribonuclease that plays a central role in rRNA processing and mRNA decay, and probably tRNA processing (PubMed:9751718, PubMed:17661085, PubMed:25248550, PubMed:32209657). Acts on 9S rRNA (the precursor of 5S rRNA) and RNAI, a molecule that controls the replication of ColE1 plasmid. Upon expression in E.coli does not purify with endogenous degradosome proteins (PubMed:9751718). Prefers 5'-monophosphorylated substrates over 5'-triphosphorylated substrates. Complements an rne temperature-sensitive mutation in E.coli, despite being considerably shorter and not able to interact with the E.coli degradosome (PubMed:10762247). Cleaves AU-rich sequences in vitro, tested with psbA2 mRNA. Complements both an rne temperature-sensitive mutation and an rng deletion in E.coli (PubMed:17661085). Acts in the degradation of psaL mRNA in the presence but not the absence of the sRNA PsrR1 (PubMed:25248550). Cleaves the rimO-crhR transcript, contributing to the very short half-life of rimO mRNA (PubMed:32209657). mRNA for psbA2, one of the core proteins in photosystem II, is degraded in the dark under control of a cis-acting AU-rich box in its 5'-UTR. RNase E cuts in this box, suggesting it is involved in this dark-induced mRNA instability. CRISPR (clustered regularly interspaced short palindromic repeat) is an adaptive immune system that provides protection against mobile genetic elements (viruses, transposable elements and conjugative plasmids). CRISPR clusters contain spacers, sequences complementary to antecedent mobile elements, and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA). Endogenous RNase E is required for correct processing of pre-crRNA for the CRISPR3 subtype III-B system in this genome (genes sll7080 to sll7095). This CRISPR3 system does not include a cas6 gene, which is the usual RNase involved in crRNA maturation. Endonucleolytic cleavage of single-stranded RNA in A- and U-rich regions. Binds 1 Mg(2+) ion per subunit. Fractionates in a 250-300 kDa region, which is too small to be the equivalent of an RNA degradosome, as occurs with E.coli RNase E (PubMed:12601000). Interacts with polynucleotide phosphorylase (PNPase, pnp), probably via the C4 Arg-rich motif (residues 665-673) (PubMed:24563514). Subcellular locations are shown upon expression in E.coli of the N-terminal domain (residues 1-396) (PubMed:22509045). Some of the protein cosediments with polysomes (PubMed:27215789). Essential, it cannot be deleted (PubMed:12601000, PubMed:17661085, PubMed:29403013). Knockdown experiments show decreased amounts of crRNA precursor processing (PubMed:29403013). Belongs to the RNase E/G family.