DEAD-box RNA helicase possibly involved in RNA degradation. Unwinds dsRNA in both 5'- and 3'-directions, has RNA-dependent ATPase activity (By similarity). Involved in cold tolerance, motility and alcohol tolerance. ATP + H2O = ADP + H(+) + phosphate Oligomerizes, may be a member of the RNA degradosome. By growth at 3 degrees Celsius (PubMed:22564273), repressed by 6% NaCl (PubMed:22820328). Growth rate decreased at 37 and 25 degrees Celsius, completely stopped at 3 degrees Celsius. No motility at 25 or 3 degrees Celsius (PubMed:22564273). Decreased growth in the presence of ethanol (PubMed:22820328). Belongs to the DEAD box helicase family. CshA subfamily.