Fig. 3.
Spr0693 interacts with Spr0694–0695 and augments the ATPase activity. a Pull-down assays. His-tagged Spr0694 and Strep-tag II tagged Spr0693 were mixed and subjected to Ni-NTA followed by Strep Tactin purification (last two lanes). The first two lanes represent the negative control with His-tagged Spr0694 and His-tagged Spr0693. The eluates of Ni-NTA and Strep Tactin were shown on the PAGE. Spr0695* represents a partially degraded fragment of Spr0695, as confirmed by mass spectrometry (Supplementary Figure 2). The protein marker presented seven bands from bottom to top (14.4, 18.4, 25, 35, 45, 66.2, 116 kDa). b The ATPase activities of Spr0694–0695, Spr0693–0694-0695, and mutants. Activity assays were performed in the proteoliposomes. For each reaction, 0.2 μM Spr0694–0695 (or mutants) dimer and/or 0.4 μM Spr0693 (or mutants) hexamer were added to the 100 μL reaction mix. The Vmax values were calculated by the Pi produced in mole with the consumption of ATP by per mole of Spr0694–0695 protein per minute. At least three independent assays were performed to calculate the means and standard deviations, and the data are presented as the means ± S.D. Two-tailed Student’s t test is used for the comparison of statistical significance. The p values of <0.05, 0.01 and 0.001 are indicated with *, ** and ***, respectively