Supplementary Figure 5: The membrane anchor does not influence the GTPase rate and lifetime of FtsZ monomers.
From: The bacterial cell division proteins FtsA and FtsZ self-organize into dynamic cytoskeletal patterns
(a) With ZipA, the average lifetime of FtsZ was slightly longer than with FtsA. Linear-log plot of FtsZ lifetime distribution with ZipA as membrane anchor (filled red circles) about 30 min after addition of GTP. Black line represents the averaged linear fit to individual lifetime distributions with <t> = 10.68 s±2.33 s (s.d. n = 24 videos with 1500 particles obtained from 5 independent experiments), which is slightly longer than for FtsZ/FtsA (p = 0.0174). (b) FtsZ GTPase activity was not affected by the membrane anchor. Bar graph shows GTPase activity of FtsZ (5 μM) or FtsZ-YFP-MTS (5 μM) and the influence of membrane anchors (His-ZipA or FtsA, 3 μM) and phospholipids (1 mg ml−1). The corresponding rates were normalized to the GTP activity of FtsZ alone (0.083/s). We found that the GTPase activity of FtsZ-YFP-MTS to be about 30% lower than of wildtype FtsZ. GTPase activities were determined using the EnzChek Phosphate Assay Kit (Molecular Probes). Error bars correspond to s.d, from n = 3 independent experiments.
