DEAD-box RNA helicase probably involved in RNA degradation. Unwinds dsRNA in both 5'- and 3'-directions (By similarity). ATP + H2O = ADP + H(+) + phosphate Homodimer (By similarity). Interacts with RNase J (rnj), might be a member of a minimal RNA degradosome complex. The RNaseJ-RhpA complex co-localizes with 70S ribosomes and polysomes; remains associated with ribosomes in the absence of RNase J. Belongs to the DEAD box helicase family.