Structural analysis of septin 2, 6, and 7 complexes.
Mammalian septins comprise a family of 13 genes that encode GTP-binding proteins. Specific combinations of septins can hetero-oligomerize and form filaments in vivo and in vitro, by mechanisms that are not understood. Using fluorescence resonance energy transfer, size exclusion chromatography, and multi-angle light scattering techniques, we have characterized the conformation of a complex of filamentous human septins, Sept2, Sept6, and Sept7. We now show that Sept6 and Sept7 interact through a parallel coiled-coil, and that Sept2 interacts with Sept6 through their C-terminal domains. We have also been able to produce soluble, stable individual septins that behave as rod-like monomers and dimers. Taken together, these observations suggest that polymerized filaments could be comprised of laterally arranged septin core subunits.
Low
Claudia
C
Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA. ccl3j@virginia.edu
Macara
Ian G
IG
D000818:Animals; D019556:COS Cells; D018797:Cell Cycle Proteins / Q000737:chemistry*; D002522:Chlorocebus aethiops; D003598:Cytoskeletal Proteins; D019281:Dimerization; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D019204:GTP-Binding Proteins / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D058112:Septins; D013050:Spectrometry, Fluorescence
D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D011108:Polymers; D010744:Phosphoric Monoester Hydrolases; D019204:GTP-Binding Proteins; C436485:SEPTIN6 protein, human; C113158:SEPTIN7 protein, human; D058112:Septins