A typical organization of nucleosomes by the Cyc8–Tup1 corepressor complex. (A) The intergenic region between HXT8 and IMA5 contains two TATA boxes (bold black) located 85 and 87 bp upstream of the start codons of HXT8 and IMA5, respectively. (B) Nucleosome occupancy and occupancy change across the promoter regions between HXT8 and IMA5. (Ovals) Canonical nucleosomes (skyblue) or the “P nucleosome” (yellow) defined in this study. Genes (purple arrows) are labeled below. Each of the top three tracks represents nucleosome occupancy in each sample. The cyc8Δ-wild-type and tup1Δ-wild-type tracks show the net occupancy difference between the corresponding samples and were plotted to show nucleosome gain (black; positive) or nucleosome loss (gray; negative). (Red dashed lines) The shift of nucleosomes between cell types. (C) Cyc8 and Tup1 binding enrichment on the promoters of HXT8 and IMA5 based on public ChIP-chip data in wild-type strains. (D) Expression change of HXT8 and IMA5 in cyc8Δ and tup1Δ strains based on microarray data.
