Fig. 1

– Organization of a septin protein. a) Three-dimensional crystal structure of human septin Sept2 (PDB: 2QA5) produced with pymol showing three orientations, each rotated 90°. Position of GTP binding is shown by solid arrow. Structures are coloured according to regions in b. Note that C-terminal extensions are not resolved in the crystal structure. b) Linear representation of a septin protein, indicating the arrangements of the major septin elements as described in the text. b) Reproduced with permission from Pan et al., [15]