FtsZ, a tubulin homologue in prokaryote cell division.

Sequence alignments convincingly demonstrate that FtsZ is a prokaryotic homologue of eukaryotic tubulins. FtsZ appears to be universal in eubacteria and archaebacteria and has also been identified in chloroplasts. Like tubulin, it appears to have a cytoskeletal role as both proteins assemble into two types of characteristic polymers in vitro - protofilament sheets and mini-rings. Recent advances in immunofluorescence and the use of green fluorescent protein have provided clear images of FtsZ localized in a ring at the septation site in bacteria, and new insights into assembly of this Z-ring.