Fig. 2: MsSepF binds to membranes and to FtsZ_CTD inducing filament bundling.

a Domain organization of SepF from M. smithii with an N-terminal amphipathic helix (M), flexible linker (L) and putative C-terminal FtsZ-binding core (C). b Negative stain electron microscope images of SUVs (100 µmol L⁻¹) and MsSepF (50 µmol L⁻¹) with (i) or without (ii) FtsZ_CTD (100 µmol L⁻¹). c Negative stain electron microscope images of FtsZ (30 µmol L⁻¹) and GTP (3 mmol L⁻¹) with (upper panel) or without (lower panel) MsSepF_core (20 µmol L⁻¹). b and c Panels show original image with an enlarged inlet that is marked by black dotted square next to it. Scale bars are 100 nm (original images) and 50 nm (inlets). These experiments were performed two times. d Boxplots showing filament diameter measurements [nm] for FtsZ + GTP (n = 130) and FtsZ + GTP + SepF_core (n = 130). Box is the inter quartile range, where the lower edge is 25^th percentile and the upper edge the 75^th percentile. Whiskers show the range between the lowest value and the highest value. Line inside each box indicates the median and x indicates the mean. Black circles are outliers. A 2-sample t-test was conducted, the result was found to be −23.8032 and the test resulted in a critical t-value of t(alpha) of 1.9692 for an alpha of 0.025. A significant difference of the diameter was found at a 5% level of significance, because the H₀ was rejected, as the modulus of the critical value was > α/2. (*) indicates that means of diameter are significantly different.