Figure 5.
H3 methylation in yeast occurs preferentially on acetylated isoforms. (A) Nuclei isolated from logarithmically growing yeast were labeled with 3H-AdoMet and acid-soluble histones were purified by RP-HPLC. The RP-HPLC profile shows the presence of a major and minor H3 peak designated as H3A and H3B, respectively. To date, we have not observed this second peak with Tetrahymena or HeLa H3. (B) RP-HPLC-purified H3A and H3B were analyzed on a 12% SDS/PAGE gel followed by examination by Coomassie staining (Lower) or fluorography (Upper). For comparison, the amount of H3B was normalized with H3A. (C) RP-HPLC-purified H3A and H3B was subjected to acid-urea gel analysis before examination by Coomassie staining (Lower) or fluorography (Upper). For comparison, H3B was normalized with H3A. Numbers to the right indicate the positions of shifted H3 isoforms.