ATP-binding RNA helicase involved in 40S ribosomal subunit biogenesis and is required for the normal formation of 18S rRNAs through pre-rRNA processing at A0, A1 and A2 sites. Required for vegetative growth. ATP + H2O = ADP + H(+) + phosphate Optimum pH is 7.4. Optimum temperature is 30 degrees Celsius. Interacts with ESF2. The Q motif is unique to and characteristic of the DEAD box family of RNA helicases and controls ATP binding and hydrolysis. Present with 3500 molecules/cell in log phase SD medium. Belongs to the DEAD box helicase family. DDX49/DBP8 subfamily.