This family includes the bacterial FtsZ family of proteins. Members of this family are involved in polymer formation. FtsZ is the polymer-forming protein of bacterial cell division. It is part of a ring in the middle of the dividing cell that is required for constriction of cell membrane and cell envelope to yield two daughter cells. FtsZ is a GTPase, like tubulin. FtsZ can polymerise into tubes, sheets, and rings in vitro and is ubiquitous in eubacteria and archaea.

1: Tubulin and FtsZ form a distinct family of GTPases. Nogales E, Downing KH, Amos LA, Lowe J; Nat Struct Biol 1998;5:451-458. PMID:9628483

2: Crystal structure of the bacterial cell-division protein FtsZ [see comments] Lowe J, Amos LA; Nature 1998;391:203-206. PMID:9428770