Figure 1

Simplified model depicting the reactions involved in the assembly of the tubulin heterodimer [18]. The colors depict the previously known regions of the cofactors and correspond to the colors ascribed to various domains in Figure 2A. The α-tubulin is gray colored and β-tubulin is black colored. For clarity, the involvement of ADP ribosylation factor-like protein 2 (Arl2) in modulating the interaction of cofactors with tubulins [18] was omitted.