The bacterial cell division protein FtsZ assembles into cytoplasmic rings in fission yeast.

During cytokinesis, most bacteria assemble a ring-like structure that is composed of the tubulin homolog FtsZ. The mechanisms regulating assembly and organization of FtsZ molecules into rings are not fully understood. Here, we express bacterial FtsZ in the fission yeast Schizosaccharomyces pombe and find that FtsZ filaments assemble into cytoplasmic rings. Investigation of the Escherichia coli FtsZ revealed that ring assembly occurred by a process of closure and/or spooling of linear bundles. We conclude that FtsZ rings can assemble in the absence of all other bacterial cytokinetic proteins and that the process might involve hydrolysis of FtsZ-bound GTP and lateral associations between FtsZ filaments.