Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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: 21.93 kDa 
• Atom Count: 1649 
• Residue Count: 182 
• Unique protein chains: 1

4QXO

Crystal structure of hSTING(group2) in complex with DMXAA

• DOI: 10.2210/pdb4QXO/pdb

• Classification: IMMUNE SYSTEM
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2014-07-21 Released: 2014-09-10 
• Deposition Author(s): Gao, P., Patel, D.J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.88 Å
• R-Value Free: 0.218 
• R-Value Work: 0.174 
• R-Value Observed: 0.176 

Literature

Binding-Pocket and Lid-Region Substitutions Render Human STING Sensitive to the Species-Specific Drug DMXAA.

Gao, P., Zillinger, T., Wang, W., Ascano, M., Dai, P., Hartmann, G., Tuschl, T., Deng, L., Barchet, W., Patel, D.J.

(2014) Cell Rep 8: 1668-1676

• PubMed: 25199835 
• DOI: 10.1016/j.celrep.2014.08.010
• Primary Citation of Related Structures:  
  4QXO, 4QXP, 4QXQ, 4QXR


• PubMed Abstract: 
  

The drug DMXAA (5,6-dimethylxanthenone-4-acetic acid) showed therapeutic promise against solid tumors in mouse models but subsequently failed in human clinical trials. DMXAA was later discovered to activate mouse, but not human, STING, an adaptor protein in the cyclic dinucleotide cGAMP-mediated signaling pathway, inducing type I interferon expression. To facilitate the development of compounds that target human STING, we combined structural, biophysical, and cellular assays to study mouse and human chimeric proteins and their interaction with DMXAA. We identified a single substitution (G230I) that enables a DMXAA-induced conformational transition of hSTING from an inactive "open" to an active "closed" state. We also identified a substitution within the binding pocket (Q266I) that cooperates with G230I and the previously identified S162A binding-pocket point substitution, rendering hSTING highly sensitive to DMXAA. These findings should facilitate the reciprocal engineering of DMXAA analogs that bind and stimulate wild-type hSTING and their exploitation for vaccine-adjuvant and anticancer drug development.

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Organizational Affiliation: 

Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA. Electronic address: [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Stimulator of interferon genes protein	A	188	Homo sapiens	Mutation(s): 7  Gene Names: TMEM173, ERIS, MITA, STING, STING1
Find proteins for Q86WV6 (Homo sapiens) Explore Q86WV6  Go to UniProtKB:  Q86WV6
NIH Common Fund Data Resources
PHAROS  Q86WV6 GTEx  ENSG00000184584

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
1YE	A	(5,6-dimethyl-9-oxo-9H-xanthen-4-yl)acetic acid C17 H14 O4 XGOYIMQSIKSOBS-UHFFFAOYSA-N

External Ligand Annotations
ID	Binding Affinity (Sequence Identity %)
1YE	Kd:  3120   nM  Binding MOAD

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.88 Å
• R-Value Free: 0.218 
• R-Value Work: 0.174 
• R-Value Observed: 0.176 
• Space Group: P 6₁ 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 62.921	α = 90
b = 62.921	β = 90
c = 196.054	γ = 120

Software Package:

Software Name	Purpose
ADSC	data collection
PHASER	phasing
PHENIX	refinement
RAPD	data reduction
RAPD	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2014-07-21 
• Released Date: 2014-09-10 
Deposition Author(s): Gao, P., Patel, D.J.

Revision History 

• Version 1.0: 2014-09-10
  Type: Initial release
  
• Version 1.1: 2014-09-24
  Changes: Database references
• Version 1.2: 2014-10-08
  Changes: Database references