DEAD-box RNA helicase involved in RNA degradation. Has RNA-dependent ATPase activity and unwinds double-stranded RNA. ATP + H2O = ADP + H(+) + phosphate ATPase activity is stimulated by interaction with RNase E. Component of the RNA degradosome, which is a multiprotein complex involved in RNA processing and mRNA degradation. Binds to RNase E (rne) and PNPase (pnp). Forms multimers. Forms a cytoskeletal-like coiled structure that extends along the length of the cell. Formation of this structure does not require the presence of RNase E, MinD and/or MreB. Belongs to the DEAD box helicase family. RhlB subfamily.