Time-dependent formation of 5′-dA (closed triangles) and Kp18FGly (open squares) with RCN anSMEcpe C276A and Kp18Cys. Reaction mixtures contained 200 μM anSMEcpe C276A, 1 mM SAM, 1 mM Kp18Cys, and 3 mM DT. The data are the averages of two independent trials, and error bars denote one standard deviation. Vmax/[ET] values for 5’-dA and Kp18FGly are 0.14 ± 0.001 min-1 and 0.001 ± 0.0001 min-1, respectively.