DEAD-box RNA helicase possibly involved in RNA degradation. May work in conjunction with the cold shock proteins to ensure proper initiation of transcription at low and optimal temperatures. Unwinds dsRNA in both 5'- and 3'-directions and shows RNA-dependent ATPase activity (By similarity). Probably has a somewhat redundant function with cshB, as cshA can partially complement the growth effects of a cshB deletion. Plays a role in adaptation to cold, oxididant and pH stress. ATP + H2O = ADP + H(+) + phosphate Oligomerizes, may be a member of the RNA degradosome. More highly expressed in lag than stationary phase at 10, 30 or 37 degrees Celsius. Induced at 10 degrees Celsius. Encoded by a monocistronic operon. Longer lag phase and slight reduction in growth rate between 20 and 45 degrees Celsius, no growth at 10 degrees Celsius. At 15 degrees Celsius the unusually long cells form large aggregates and are curved at the pole, with incompletely divided, thickened internal membranes. Decreased growth in the presence of H(2)O(2), diamide and at acidic and basic pH. Belongs to the DEAD box helicase family. CshA subfamily.