Figure 5
The phosphorylation kinetics of the human PER2 peptide is more uniform than the kinetics of the p63 PAD peptide. A C670A mutant was used to avoid problems with oxidation. (a) Phosphorylation kinetics of the five serines of the PER2 peptide with the CK1δ kinase domain in a 100:1 ratio. A duplicate with a 250:1 ratio was measured showing as expected slower but otherwise very similar kinetics (Supplementary Fig. S13). (b) Phosphorylation kinetics of S662 with different mutants of the CK1δ C-terminal domain. The same mutation groups as for the p63 PAD peptide experiments were used. Similar to the results with the p63 PAD peptide mutating the three residues Thr344A, Ser361A, Ser370A shows the strongest effect. Experiments were measured in duplicate, the data shown represent one replicate. (c) Sequence of the PER2 peptide, flanked by GB1 N- as well as C-terminally. The five phosphorylation sites are marked red.
