PhDph5-catalyzed PhEF2 methylation monitored using methyl-14C SAM. The PhDph5 activity assays were set up with 30 µM ACP-modified PhEF2, 60 µM PhDph5, and different SAM concentrations (0 µM, 2.5 µM, 5 µM, 10 µM, 20 µM, 30 µM and 50 µM). The reactions were incubated at 37°C for 30 min. Bottom panel shows the Coomassie blue-stained gel; top panel shows the autoradiography. The ratios of SAM to PhEF2 were shown at the bottom of the image.