ATP-dependent RNA helicase involved in 40S ribosomal subunit biogenesis. Required for the processing and cleavage of 35S pre-rRNA at sites A0, A1, and A2, leading to mature 18S rRNA. ATP + H2O = ADP + H(+) + phosphate Interacts with the U3 snoRNA and is associated with the 90S and 40S pre-ribosomes. This association requires the presence of RRP5. Interacts also with OSH3 (By similarity). 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. DDX52/ROK1 subfamily.