DEAD-box RNA helicase involved in ribosome assembly. Has RNA-dependent ATPase activity and unwinds double-stranded RNA. May play a role in the interconversion of ribosomal RNA-folding intermediates that are further processed by DeaD or SrmB during ribosome maturation. ATP + H2O = ADP + H(+) + phosphate ATPase activity is stimulated by both long RNAs and short oligoribonucleotides. Interacts with PcnB. Interacts in vitro with RNase E. Ribosome-associated. Can either bind to the intact 70S ribosome or to individual ribosomal subunits. Transiently induced by cold shock in a PNPase-dependent fashion (PubMed:14527658). Induced by the transcriptional regulator CecR (PubMed:27112147). In vitro, can replace RhlB in degradosome and facilitate the degradation of RNA by PNPase. Belongs to the DEAD box helicase family. RhlE subfamily.