(A) Genome-wide ubiquitin binding profiles identify numerous regions of H2B-ubiquitylation in WT cells and distinct sites of non-H2B ubiquitylation ('ubiquitin-hotspot', ub-hotspot, ub-HS) which persist in h2b-K123R and rad6∆ strains, and increase in cdc48 mutants (cdc48-6). A 90 kb stretch of chromosome XIII (ChrXIII) is depicted. Chromatin immunoprecipitation was performed using the FK2 ubiquitin antibody (see also Appendix Fig. S1A) and enriched DNA was analyzed on NimbleGen arrays (Chip-chip). DNA from non-specific IgG-ChIP experiments served as background control. Significantly enriched regions are marked by bars above the respective ChIP-chip tracks and are summarized in Dataset EV1. Data represent means from two independent replicates, except for ubiquitin (FK2) in rad6∆ and IgG-ChIP in WT (n = 1). All experiments, including those using cdc48-6 and other temperature-sensitive (ts) alleles, were performed at 30°C (semipermissive temperature for ts-alleles) unless stated otherwise. 