title: Structural and biochemical properties of Sept7, a unique septin required for filament formation.
abstract: Septins constitute a family of conserved guanine nucleotide binding proteins found in a wide range of organisms from fungi to mammals. Members of the family share a canonical G-domain with N- and C-terminal extensions. G-domains assemble into hetero-oligomeric complexes which form non-polarised filaments or rings. Linear filaments are formed between the G-domains using either the guanine nucleotide binding site (G interface) or N- and C-terminal extensions (NC interface). Sept7 is a unique among the 13 human septins in that it occupies the ends of hexameric building blocks which assemble into non-polarised filaments. To gain insight into its particular properties we performed structural and biochemical studies on Sept7. We solved the crystal structure of a Sept7 dimer in the GDP-bound state. The structure and biochemistry of Sept7 provide new insights into the dynamics of the G interface and outline the differences in the properties of Sept7 compared to the members of group 2 septins.
authors.affiliation: Structural Biology Group, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
authors.forename: Eldar
authors.initials: E
authors.lastname: Zent
authors.forename: Ingrid
authors.initials: I
authors.lastname: Vetter
authors.forename: Alfred
authors.initials: A
authors.lastname: Wittinghofer
mesh_terms: D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D003599:Cytoskeleton / Q000378:metabolism*; D006801:Humans; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D058112:Septins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; C113158:SEPTIN7 protein, human; D058112:Septins