-!- RNase E is a bacterial ribonuclease that plays a role in the processing of ribosomal RNA (9S to 5S rRNA), the chemical degradation of bulk cellular RNA, the decay of specific regulatory, messenger and structural RNAs and the control of plasmid DNA replication. -!- The enzyme binds to monophosphorylated 5' ends of substrates but exhibits sequential cleavages in the 3' to 5' direction. -!- 2'-O-methyl nucleotide substitutions at RNase E binding sites do not prevent binding but do prevent cleavage of non-modified target sequences 5' to that locus. -!- In Escherichia coli, the enzyme is found in the RNA degradosome. -!- The C-terminal half of the protein contains binding sites for the three other major degradosomal components, the DEAD-box RNA helicase Rh1B, EC 4.1.1.11 and EC 2.7.7.8. -!- Formerly EC 3.1.26.n1.