Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 73958.52 
• Atom Count: 3620 
• Residue Count: 630 
• Unique protein chains: 1

2QA5

Crystal structure of Sept2 G-domain

• DOI: 10.2210/pdb2QA5/pdb

• Classification: CELL CYCLE STRUCTURAL PROTEIN
• Organism(s): Homo sapiens
• Expression System: Escherichia coli


• Deposited: 2007-06-14 Released: 2007-08-07 
• Deposition Author(s): Sirajuddin, M., Wittinghofer, A.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.4 Å
• R-Value Free: 0.314 
• R-Value Work: 0.280 

Literature

Structural insight into filament formation by mammalian septins.

Sirajuddin, M., Farkasovsky, M., Hauer, F., Kuhlmann, D., Macara, I.G., Weyand, M., Stark, H., Wittinghofer, A.

(2007) Nature 449: 311-315

• PubMed: 17637674 
• DOI: 10.1038/nature06052
• Primary Citation of Related Structures:  
  2QAG


• PubMed Abstract: 
  

Septins are GTP-binding proteins that assemble into homo- and hetero-oligomers and filaments. Although they have key roles in various cellular processes, little is known concerning the structure of septin subunits or the organization and polarity of septin complexes. Here we present the structures of the human SEPT2 G domain and the heterotrimeric human SEPT2-SEPT6-SEPT7 complex. The structures reveal a universal bipolar polymer building block, composed of an extended G domain, which forms oligomers and filaments by conserved interactions between adjacent nucleotide-binding sites and/or the amino- and carboxy-terminal extensions. Unexpectedly, X-ray crystallography and electron microscopy showed that the predicted coiled coils are not involved in or required for complex and/or filament formation. The asymmetrical heterotrimers associate head-to-head to form a hexameric unit that is nonpolarized along the filament axis but is rotationally asymmetrical. The architecture of septin filaments differs fundamentally from that of other cytoskeletal structures.

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Organizational Affiliation: 

Abteilung Strukturelle Biologie, Max-Planck-Institut für molekulare Physiologie, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Septin-2	A, B	315	Homo sapiens	Mutation(s): 0  Gene Names: SEPTIN2 (DIFF6, KIAA0158, NEDD5, SEPT2)
Find proteins for Q15019 (Homo sapiens) Go to UniProtKB:  Q15019

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
GDP	A, B	GUANOSINE-5'-DIPHOSPHATE C10 H15 N5 O11 P2 QGWNDRXFNXRZMB-UUOKFMHZSA-N

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
MSE	A, B	L-PEPTIDE LINKING	C5 H11 N O2 Se		MET

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.4 Å
• R-Value Free: 0.314 
• R-Value Work: 0.280 
• Space Group: C 1 2 1

Unit Cell:

Length (Å)	Angle (°)
a = 162.960	α = 90.00
b = 53.920	β = 128.37
c = 110.270	γ = 90.00

Software Package:

Software Name	Purpose
PDB_EXTRACT	data extraction
REFMAC	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2007-06-14 
• Released Date: 2007-08-07 
• Deposition Author(s): Sirajuddin, M., Wittinghofer, A.

Revision History 

• Version 1.0: 2007-08-07
  Type: Initial release
• Version 1.1: 2011-07-13
  Type: Version format compliance