Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 5-mer - ABCDE Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Homo 5-mer -A5 

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

Macromolecule Content

• Total Structure Weight: 36923.73 
• Atom Count: 2497 
• Residue Count: 317 
• Unique protein chains: 5

1KIL

Three-dimensional structure of the complexin/SNARE complex

• DOI: 10.2210/pdb1KIL/pdb

• Classification: MEMBRANE PROTEIN
• Organism(s): Homo sapiens, Rattus norvegicus
• Expression System: Escherichia coli BL21(DE3)


• Deposited: 2001-12-03 Released: 2002-03-13 
• Deposition Author(s): Chen, X., Tomchick, D., Kovrigin, E., Arac, D., Machius, M., Sudhof, T.C., Rizo, J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.3 Å
• R-Value Free: 0.305 
• R-Value Work: 0.245 

Literature

Three-dimensional structure of the complexin/SNARE complex.

Chen, X., Tomchick, D.R., Kovrigin, E., Arac, D., Machius, M., Sudhof, T.C., Rizo, J.

(2002) Neuron 33: 397-409

• PubMed: 11832227 


• PubMed Abstract: 
  

During neurotransmitter release, the neuronal SNARE proteins synaptobrevin/VAMP, syntaxin, and SNAP-25 form a four-helix bundle, the SNARE complex, that pulls the synaptic vesicle and plasma membranes together possibly causing membrane fusion. Complexin binds tightly to the SNARE complex and is essential for efficient Ca(2+)-evoked neurotransmitter release. A combined X-ray and TROSY-based NMR study now reveals the atomic structure of the complexin/SNARE complex. Complexin binds in an antiparallel alpha-helical conformation to the groove between the synaptobrevin and syntaxin helices. This interaction stabilizes the interface between these two helices, which bears the repulsive forces between the apposed membranes. These results suggest that complexin stabilizes the fully assembled SNARE complex as a key step that enables the exquisitely high speed of Ca(2+)-evoked neurotransmitter release.

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Organizational Affiliation: 

Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Synaptobrevin SNARE motif	A	66	Rattus norvegicus	Mutation(s): 0  Gene Names: Vamp2 (Syb2)
Find proteins for P63045 (Rattus norvegicus) Go to UniProtKB:  P63045

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details
Syntaxin SNARE motif short	B	62	Rattus norvegicus	Mutation(s): 0  Gene Names: Stx1a (Sap)
Find proteins for P32851 (Rattus norvegicus) Go to UniProtKB:  P32851

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details
SNAP-25 N-terminal SNARE motif	C	74	Homo sapiens	Mutation(s): 0  Gene Names: SNAP25 (SNAP)
Find proteins for P60880 (Homo sapiens) Go to Gene View: SNAP25 Go to UniProtKB:  P60880

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details
SNAP-25 C-terminal SNARE motif	D	66	Homo sapiens	Mutation(s): 0  Gene Names: SNAP25 (SNAP)
Find proteins for P60880 (Homo sapiens) Go to Gene View: SNAP25 Go to UniProtKB:  P60880

Entity ID: 5
Molecule	Chains	Sequence Length	Organism	Details
Complexin I SNARE-complex binding region	E	49	Rattus norvegicus	Mutation(s): 0  Gene Names: Cplx1
Find proteins for P63041 (Rattus norvegicus) Go to UniProtKB:  P63041

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
MG	A, C	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.3 Å
• R-Value Free: 0.305 
• R-Value Work: 0.245 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length (Å)	Angle (°)
a = 40.489	α = 90.00
b = 60.425	β = 90.00
c = 159.787	γ = 90.00

Software Package:

Software Name	Purpose
HKL-2000	data reduction
HKL-2000	data scaling
HKL-2000	data collection
AMoRE	phasing
CNS	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2001-12-03 
• Released Date: 2002-03-13 
• Deposition Author(s): Chen, X., Tomchick, D., Kovrigin, E., Arac, D., Machius, M., Sudhof, T.C., Rizo, J.

Revision History 

• Version 1.0: 2002-03-13
  Type: Initial release
• Version 1.1: 2008-04-27
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance