Fig. 8

Thermophoresis binding of DNA Pol1B with Twinkle domains. The DNA polymerase 1B was labeled as the target protein at 20 nM concentration and assayed in microscale thermophoresis experiments with Twinkle, the primase and helicase domains, and the zinc finger subdomain. The thermophoretic data was fitted to the Kd equation described in materials and methods. The zinc finger subdomain was able to bind to the PolB and a Kd was measured at 2.17 μM. The RNAP subdomain (red) did not show binding (data not shown). The primase and helicase domain were able interact with the polymerase with a Kd of 0.81 and 1.97 μM respectively. The full-length protein interacts with a Kd of 1.26 μM. All proteins were titrated in 16 serial dilutions from different concentrations. Graphs were plotted at x axis with enzyme concentration and at the y axis with normalized fluorescence. Error bars represent the standard error for three measurements