Fig. 4.

Novel MutT catalytic activities. The reactions were monitored by P_i sensor at pH 7.6 and 37 °C. (A) Hydrolysis of 5 μM 5-methyl-dCTP (circles) and dCTP (triangles). Initial velocities, v_i (nM P_i/s), are plotted against MutT concentration (nM) in the presence (solid circles and triangles) or absence (empty circles) of PPase. The background (no MutT) activities of 0.23 nM P_i/s (solid circles and triangles) and 0.36 nM P_i/s (empty circles) were subtracted from each data point. (B) Hydrolysis of 8-oxo-dGTP either in the presence (solid circles and solid line) or in the absence (empty circles and dashed line) of PPase.