Multiple alignment of the central regions of representative septins. Amino-acid sequences of the representative septins were aligned using MacVector. Acidic, basic and hydrophobic residues are in purple, blue, and yellow respectively. The GTPase motifs that are conserved in this family - G-1, G-3 and G-4 - are indicated above the sequence. A few other conserved stretches of hydrophobic and charged residues are also recognizable. Species abbreviations are as in Figure 1.