Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction | Predict Membrane 

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

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

Macromolecule Content

• Total Structure Weight: 53.58 kDa 
• Atom Count: 3034 
• Modelled Residue Count: 398 
• Deposited Residue Count: 476 
• Unique protein chains: 2

4MQS

Structure of active human M2 muscarinic acetylcholine receptor bound to the agonist iperoxo

• PDB DOI: 10.2210/pdb4MQS/pdb

• Classification: SIGNALING PROTEIN
• Organism(s): Homo sapiens, Lama glama
• Expression System: Spodoptera frugiperda, Escherichia coli BL21(DE3)
• Mutation(s): Yes 
• Membrane Protein: Yes  OPMPDBTMMemProtMDmpstruc


• Deposited: 2013-09-16 Released: 2013-11-27 
• Deposition Author(s): Kruse, A.C., Ring, A.M., Manglik, A., Hu, J., Hu, K., Eitel, K., Huebner, H., Pardon, E., Valant, C., Sexton, P.M., Christopoulos, A., Felder, C.C., Gmeiner, P., Steyaert, J., Weis, W.I., Garcia, K.C., Wess, J., Kobilka, B.K.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.50 Å
• R-Value Free: 0.298 
• R-Value Work: 0.249 
• R-Value Observed: 0.254 

Literature

Activation and allosteric modulation of a muscarinic acetylcholine receptor.

Kruse, A.C., Ring, A.M., Manglik, A., Hu, J., Hu, K., Eitel, K., Hubner, H., Pardon, E., Valant, C., Sexton, P.M., Christopoulos, A., Felder, C.C., Gmeiner, P., Steyaert, J., Weis, W.I., Garcia, K.C., Wess, J., Kobilka, B.K.

(2013) Nature 504: 101-106

• PubMed: 24256733 
• DOI: 10.1038/nature12735
• Primary Citation of Related Structures:  
  4MQS, 4MQT


• PubMed Abstract: 
  

Despite recent advances in crystallography and the availability of G-protein-coupled receptor (GPCR) structures, little is known about the mechanism of their activation process, as only the β2 adrenergic receptor (β2AR) and rhodopsin have been crystallized in fully active conformations. Here we report the structure of an agonist-bound, active state of the human M2 muscarinic acetylcholine receptor stabilized by a G-protein mimetic camelid antibody fragment isolated by conformational selection using yeast surface display. In addition to the expected changes in the intracellular surface, the structure reveals larger conformational changes in the extracellular region and orthosteric binding site than observed in the active states of the β2AR and rhodopsin. We also report the structure of the M2 receptor simultaneously bound to the orthosteric agonist iperoxo and the positive allosteric modulator LY2119620. This structure reveals that LY2119620 recognizes a largely pre-formed binding site in the extracellular vestibule of the iperoxo-bound receptor, inducing a slight contraction of this outer binding pocket. These structures offer important insights into the activation mechanism and allosteric modulation of muscarinic receptors.

---

Organizational Affiliation: 

1] Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, California 94305, USA [2].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Muscarinic acetylcholine receptor M2	A	351	Homo sapiens	Mutation(s): 6  Gene Names: CHRM2 Membrane Entity: Yes
UniProt & NIH Common Fund Data Resources
Find proteins for P08172 (Homo sapiens) Explore P08172  Go to UniProtKB:  P08172
PHAROS:  P08172 GTEx:  ENSG00000181072

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Nanobody 9-8	B	125	Lama glama	Mutation(s): 0

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
IXO	C [auth A]	4-(4,5-dihydro-1,2-oxazol-3-yloxy)-N,N,N-trimethylbut-2-yn-1-aminium C10 H17 N2 O2 WXXOCGISBCTWPW-UHFFFAOYSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
IXO	BindingDB:  4MQS	Ki: min: 2.2, max: 257 (nM) from 6 assay(s)
		EC50: min: 0.08, max: 0.28 (nM) from 3 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.50 Å
• R-Value Free: 0.298 
• R-Value Work: 0.249 
• R-Value Observed: 0.254 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 62.896	α = 90
b = 78.13	β = 90
c = 163.482	γ = 90

Software Package:

Software Name	Purpose
HKL-2000	data collection
PHASER	phasing
PHENIX	refinement
HKL-2000	data reduction
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2013-09-16 
• Released Date: 2013-11-27 
Deposition Author(s): Kruse, A.C., Ring, A.M., Manglik, A., Hu, J., Hu, K., Eitel, K., Huebner, H., Pardon, E., Valant, C., Sexton, P.M., Christopoulos, A., Felder, C.C., Gmeiner, P., Steyaert, J., Weis, W.I., Garcia, K.C., Wess, J., Kobilka, B.K.

Revision History  

• Version 1.0: 2013-11-27
  Type: Initial release
  
• Version 1.1: 2013-12-04
  Changes: Database references
• Version 1.2: 2013-12-18
  Changes: Database references
• Version 1.3: 2017-07-05
  Changes: Source and taxonomy