Insulator protein Su(Hw) recruits SAGA and Brahma complexes and constitutes part of Origin Recognition Complex-binding sites in the Drosophila genome

摘要: Despite increasing data on the properties of replication origins, molecular mechanisms underlying origin recognition complex (ORC) positioning in genome are still poorly understood. The Su(Hw) protein accounts for activity best-studied Drosophila insulators. Here, we show that recruits histone acetyltransferase SAGA and chromatin remodeler Brahma to Su(Hw)-dependent insulators, which gives rise regions with low nucleosome density creates conditions ORC binding. Depletion leads a dramatic drop levels SAGA, subunits significant increase whereas artificial recruitment itself is sufficient subsequent In contrast majority origins associate promoters active genes, Su(Hw)-binding sites constitute small proportion (6%) ORC-binding localized preferentially transcriptionally inactive termed BLACK BLUE chromatin. We suggest key determinants DNA-binding proteins different DNA regulatory elements, including enhancers. first example such protein.