Functional mapping of Saccharomyces cerevisiae Prp45 identifies the SNW domain as essential for viability.

The essential gene product Prp45 (379 aa) of Saccharomyces cerevisiae is a highly conserved, but N-terminally abridged, ortholog of the human transcriptional coactivator SKIP, which is involved in TGFbeta, Notch, and steroid hormone signaling. We used a diploid strain harboring PRP45 deletion, which is inviable in the haploid, to test for complementation with the truncated versions of Prp45. The N-terminal half of the protein (aa 1 to 190), denoted as the SNW domain, was found sufficient to support the essential function.