Figure 2.

H2Bub in S. pombe is mediated by conserved enzymes. (A) Strains carrying both the htb1-Flag allele and one of the indicated mutations were analyzed by anti-Flag Western blot. Bands corresponding to H2B-Flag and its ubiquitylated form are indicated on the right. The asterisk denotes a probable H2B–SUMO conjugate. (B) Whole-cell extracts from the indicated strains were subjected to anti-myc immunoprecipitations, and the bound fractions were analyzed by SDS-PAGE and Coommassie staining. Bands identified by tandem mass spectrometry or by anti-myc Western blotting are denoted on the right (Brl1 and Brl2 have nearly identical molecular masses and thus were not resolved). The arrow denotes a contaminating protein. On the left are molecular weight markers (in kilodaltons).