Septins are a conserved family of GTP-binding proteins that assemble into a 
highly ordered array of filaments at the mother bud neck in Saccharomyces 
cerevisiae cells. Many molecular functions and mechanisms of the septins in S. 
cerevisiae were already uncovered. However, structural information is only 
available from modeling the crystallized subunits of the human septins into the 
EM cryomicroscopy data of the yeast hetero-octameric septin rod. Octameric rods 
are the building block of septin filaments in yeast. We present here the first 
crystal structure of Cdc11, the terminal subunit of the octameric rod and 
discuss its structure in relation to its human homologues. Size exclusion 
chromatography analysis revealed that Cdc11 forms homodimers through its 
C-terminal coiled coil tail.