Figure 4.
PAPD1 has activity towards all four nucleotides in vitro. (A). Catalytic activity of PAPD1 towards the four nucleotides, ATP, GTP, CTP and UTP. 10 and 50 ng of the wild-type (WT) enzyme were used, and 50 ng of the D325A mutant were also assayed as a control. (B). Concentration titration of the activity of PAPD1 towards ATP and UTP. The concentrations used for the nucleotides are indicated. (C). The poly(A) and poly(U) polymerase reaction of PAPD1 follows Michaelis-Menten kinetics. The error bars represent ± 1SD.