Probable ATP-dependent RNA helicase. Component of the nucleolar ribosomal RNA (rRNA) processing machinery that may be involved in ribosome biogenesis. ATP + H2O = ADP + H(+) + phosphate The Q motif is unique to and characteristic of the DEAD box family of RNA helicases and controls ATP binding and hydrolysis. The C-terminal domain regulates nucleolar localization. Belongs to the DEAD box helicase family. DDX27/DRS1 subfamily.