Required for pre-mRNA splicing as component of the spliceosome (PubMed:20423332, PubMed:20841358, PubMed:25296192, PubMed:29360106). Contributes to pre-mRNA splicing after spliceosome formation and prior to the first transesterification reaction. ATP + H2O = ADP + H(+) + phosphate Component of pre-catalytic spliceosome complexes (PubMed:20423332, PubMed:20841358, PubMed:25296192, PubMed:29360106). Interacts with GPKOW. Expressed in the spleen, thyroid and testis. Also expressed in the brain and cerebellum. The disease is caused by variants affecting the gene represented in this entry. Belongs to the DEAD box helicase family. DEAH subfamily. DDX16/PRP8 sub-subfamily. Extended N-terminus.