Figure 1

H2B ubiquitylation is enriched at gene coding regions and correlates with transcriptional activity and gene length. (A) H2BK123ub1 is enriched at gene coding regions. H2BK123ub1 ChDIP-chip was performed using a high-resolution oligonucleotide tiling array. The log2 ratio of ubiquitylated H2B in wild type yeast cells was subjected to the averaged gene analysis (detailed in Materials and Methods). (B) H2BK123ub1 levels at various genomic locations calculated as in (A). ORF: open read frame; intergenic region; telomere: the average of the last 20 Kb of each chromosome; rDNA: ribosomal DNA; HM: the silent HMRa and HMLa loci. (C) H2BK123ub1 levels are proportional to transcription rate. All yeast genes were divided into five subclasses according to transcription rate [35]. Composite H2BK123ub1 profiles for each subclass are shown on averaged genes based on the analysis from Pokholok et al. (2005). (D) H2BK123ub1 levels are correlated with gene length. All yeast genes were divided into 8 subclasses according to the length of their coding regions. Composite H2BK123ub1 profiles for each subclass are shown on averaged genes as in (C). (E) Genes with transcription rates below 16 mRNA/hour were selected and divided into subclasses based on gene length as in (D). The average enrichment of H2BK123ub1in each subclass was plotted as a function of the averaged genes. (F) Genes with transcription rates greater than or equal to 16 mRNA/hour were selected and divided into subclasses based on gene length as in (D) and then plotted as in (E).