The only exoribonuclease present in Haloferax volcanii has an unique response to temperature changes

► RNase R is the only enzyme described with exoribonucleolytic activity in Haloferax. ► Characterization of H. volcanii RNase R exonucleolytic and RNA binding activities. ► Protein predicted to be like E. coli RNase R but at 37 °C behaves like RNase II. ► Unusual protein with two different activities according to the temperature. ► Disclosure of additional levels of regulation by RNases during RNA decay.