FIGURE 1:

Ume6p is a substrate of acetyltransferase complexes. (A) Affinity-purified acetyltransferase fractions or recombinant Gcn5p were incubated with GST-Ume6^721-831 or the four histones. The reactions were split, with one-half separated by PAGE and fluorographed or quantitated (B) by liquid scintillation spectroscopy (dpm). (C) Wild-type strain RSY10 harboring GAL-T7-UME6 expression plasmid (+) or vector control (–) was grown in the presence of ¹⁴C-acetyl-CoA. Extracts derived from these cultures were immunoprecipitated with T7 mAb, and the immunoprecipitates were separated by PAGE and then visualized by fluorography. Whole-cell extracts (WCEs) controlled for equal protein loading and labeling. (D) Acetylation occurs in a region adjacent to the C₆ zinc-cluster DNA-binding domain of Ume6p. The sequence of the last 110 amino acids of Ume6p (726–836) is presented. The acetylated residues are indicated by the asterisks. The cysteines making up the C₆ zinc cluster are in boldface and boxed. The Ime1p and Sin3p interaction domains are indicated.