Requirement of the RNA Helicase-like Protein PRP22 for Release of Messenger RNA from Spliceosomes

The product of the yeast PRP22 gene acts late in the splicing of yeast pre-messenger RNA, mediating the release of the spliced mRNA from the spliceosome. The predicted PRP22 protein sequence shares extensive homology with that of PRP2 and PRP16 proteins, which are also involved in nuclear pre-mRNA splicing. The homologous region contains sequence elements characteristic of several demonstrated or putative ATP-dependent RNA helicases. A putative RNA-binding motif originally identified in bacterial ribosomal protein S1 and Escherichia coli polynucleotide phosphorylase has also been found in PRP22.