Fig. 3.

Z rings without GTP hydrolysis, inside and outside tubular liposomes. (a) GTPase dead FtsZ(D212G)-YFP-mts assembled Z rings inside tubular liposomes. 8 μM FtsZ was mixed with liposomes and 1 mM GTP, followed by the application of a coverslip. Z rings are located at constriction sites. (b) The mutant mts-FtsZ(D212G)-YFP (N terminal mts), assembled inside-out Z rings on the outside of tubular liposomes. Again Z rings are seen at sites of constriction. (c) Inside-out Z rings were assembled with 8 μM mts-FtsZ-YFP plus 1 mM GMPCPP. The inside-out Z rings were observed at sites of constriction. The rings assembled in GMPCPP showed small rocking movements but were much more static than rings assembled in GTP (Supporting Information Movie S3). (d) Another example of inside-out Z rings assembled from mts-FtsZ-YFP plus 1 mM GMPCPP. This liposome is densely coated with inside-out Z rings at the top and bottom, but devoid of Z rings in the slightly bulged middle segment. The arrows indicate the appearance of new rings (as small dots on one side of the bulge), which slide down to the narrower regions. Supporting Information Movie S4 shows the initiation of new Z rings more clearly. Bars indicate 5 μm.