ATP-dependent RNA helicase involved in pre-mRNA splicing. Required for the export of mRNA out of the nucleus. In addition to ssRNA and dsRNA, binds dsDNA, but not ssDNA. ATP + H2O = ADP + H(+) + phosphate Interacts with ALY2 and MOS11. Localizes predominantly to euchromatic regions of the nucleoplasm. A number of isoforms are produced. According to EST sequences. The Q motif is unique to and characteristic of the DEAD box family of RNA helicases and controls ATP binding and hydrolysis. Belongs to the DEAD box helicase family. DECD subfamily.