This family includes the tubulin alpha, beta and gamma chains. Members of this family are involved in polymer formation. Tubulins are GTPases. FtsZ can polymerise into tubes, sheets, and rings in vitro and is ubiquitous in eubacteria and archaea. Tubulin is the major component of microtubules. (The FtsZ GTPases have been split into their won family).

1: Structure of the alphabeta tubulin dimer by electron crystallography. Nogales E, Wolf SG, Downing KH; Nature 1998;391:199-203. PMID:9428769

2: 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

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