Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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Protein Workshop | Ligand Explorer

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 54087.40 
• Atom Count: 3256 
• Residue Count: 466 
• Unique protein chains: 1

1XA6

Crystal Structure of the Human Beta2-Chimaerin

• DOI: 10.2210/pdb1XA6/pdb

• Classification: SIGNALING PROTEIN
• Organism(s): Homo sapiens
• Expression System: Spodoptera frugiperda


• Deposited: 2004-08-25 Released: 2004-11-23 
• Deposition Author(s): Canagarajah, B., Leskow, F.C., Ho, J.Y., Mischak, H., Saidi, L.F., Kazanietz, M.G., Hurley, J.H.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.2 Å
• R-Value Free: 0.298 
• R-Value Work: 0.252 

Literature

Structural mechanism for lipid activation of the Rac-specific GAP, beta2-chimaerin.

Canagarajah, B., Leskow, F.C., Ho, J.Y., Mischak, H., Saidi, L.F., Kazanietz, M.G., Hurley, J.H.

(2004) Cell 119: 407-418

• PubMed: 15507211 
• DOI: 10.1016/j.cell.2004.10.012


• PubMed Abstract: 
  

The lipid second messenger diacylglycerol acts by binding to the C1 domains of target proteins, which translocate to cell membranes and are allosterically activated. Here we report the crystal structure at 3.2 A resolution of one such protein, beta2-chimaerin, a GTPase-activating protein for the small GTPase Rac, in its inactive conformation. The structure shows that in the inactive state, the N terminus of beta2-chimaerin protrudes into the active site of the RacGAP domain, sterically blocking Rac binding. The diacylglycerol and phospholipid membrane binding site on the C1 domain is buried by contacts with the four different regions of beta2-chimaerin: the N terminus, SH2 domain, RacGAP domain, and the linker between the SH2 and C1 domains. Phospholipid binding to the C1 domain triggers the cooperative dissociation of these interactions, allowing the N terminus to move out of the active site and thereby activating the enzyme.

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Organizational Affiliation: 

Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD 20892, USA.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Beta2-chimaerin	A	466	Homo sapiens	Mutation(s): 0  Gene Names: CHN2 (ARHGAP3, BCH)
Find proteins for P52757 (Homo sapiens) Go to Gene View: CHN2 Go to UniProtKB:  P52757

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
ZN	A	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.2 Å
• R-Value Free: 0.298 
• R-Value Work: 0.252 
• Space Group: P 6₁ 2 2

Unit Cell:

Length (Å)	Angle (°)
a = 131.090	α = 90.00
b = 131.090	β = 90.00
c = 288.750	γ = 120.00

Software Package:

Software Name	Purpose
DENZO	data reduction
CNS	refinement
SOLVE	phasing
SCALEPACK	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2004-08-25 
• Released Date: 2004-11-23 
• Deposition Author(s): Canagarajah, B., Leskow, F.C., Ho, J.Y., Mischak, H., Saidi, L.F., Kazanietz, M.G., Hurley, J.H.

Revision History 

• Version 1.0: 2004-11-23
  Type: Initial release
• Version 1.1: 2008-04-30
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance