Component of the U5 snRNP complex required for pre-mRNA splicing. Binds GTP. Belongs to the 40S cdc5-associated complex (or cwf complex), a spliceosome sub-complex reminiscent of a late-stage spliceosome composed of the U2, U5 and U6 snRNAs and at least brr2, cdc5, cwf2/prp3, cwf3/syf1, cwf4/syf3, cwf5/ecm2, spp42/cwf6, cwf7/spf27, cwf8, cwf9, cwf10, cwf11, cwf12, prp45/cwf13, cwf14, cwf15, cwf16, cwf17, cwf18, cwf19, cwf20, cwf21, cwf22, cwf23, cwf24, cwf25, cwf26, cyp7/cwf27, cwf28, cwf29/ist3, lea1, msl1, prp5/cwf1, prp10, prp12/sap130, prp17, prp22, sap61, sap62, sap114, sap145, slu7, smb1, smd1, smd3, smf1, smg1 and syf2. Belongs to the TRAFAC class translation factor GTPase superfamily. Classic translation factor GTPase family. EF-G/EF-2 subfamily.