SNF11, A NEW COMPONENT OF THE YEAST SNF-SWI COMPLEX THAT INTERACTS WITH A CONSERVED REGION OF SNF2

The yeast SNF-SWI complex is required for transcriptional activation o f diverse genes and has been shown to alter chromatin structure. The c omplex has at least 10 components, including SNF2/SWI2, SNF5, SNF6, SW I1/ADR6, and SW13, and has been widely conserved in eukaryotes. Here w e report the characterization of a new component. We identified protei ns that interact in the two-hybrid system with the N-terminal region o f SNF2, preceding the ATPase domain. In addition to SWI3, we recovered a new 19-kDa protein, designated SNF11. Like other SNF/SWI proteins, SNF11 functions as a transcriptional activator in genetic assays. SNE1 1 interacts with SNF2 in vitro and copurifies with the SNF-SWI complex from yeast cells. Using a specific antibody, we showed that SNF11 coi mmunoprecipitates with members of the SNF-SWI complex and that SNF11 i s tightly and stoichiometrically associated with the complex. Furtherm ore, SNF11 was detected in purified SNF-SWI complex by staining with C oomassie blue dye; its presence previously went unrecognized because i t does not stain with silver. SNF11 interacts with a 40-residue sequen ce of SNF2 that is highly conserved, suggesting that SNF11 homologs ex ist in other organisms.