Figure 2.

Methyltransferase activity and automethylation of different engineered Clr4 variants compared to wild type (WT). Exemplary autoradiographic gel images of in vitro methyltransferase assays with Clr4 WT and its mutants A454R, D456S/F457T, A454R/D456S/F457T, K455R, K455R/K472R and K455M (A). The red asterisks indicate the Clr4 automethylation signal. Quantitative analysis of two to four independent experiments revealed the histone peptide methylation activity (B) and automethylation levels (C) of all mutants, which are represented relative to WT enzyme. The mean values are indicated by the bars and the individual data points as circles. In panel (C), results obtained with and without peptide were combined. The p-values of the differences in automethylation and methyltransferase activities between WT and mutants are listed in Supplementary Table S1.