Structure of active human M2 muscarinic acetylcholine receptor bound to the agonist iperoxo and allosteric modulator LY2119620

Experimental Data Snapshot

  • Resolution: 3.70 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.250 
  • R-Value Observed: 0.255 

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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

  • DOI: https://doi.org/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].

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Muscarinic acetylcholine receptor M2351Homo sapiensMutation(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 Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP08172
Sequence Annotations
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Nanobody 9-8125Lama glamaMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on 2CU

Download Ideal Coordinates CCD File 
D [auth A]3-amino-5-chloro-N-cyclopropyl-4-methyl-6-[2-(4-methylpiperazin-1-yl)-2-oxoethoxy]thieno[2,3-b]pyridine-2-carboxamide
C19 H24 Cl N5 O3 S
Query on IXO

Download Ideal Coordinates CCD File 
C [auth A]4-(4,5-dihydro-1,2-oxazol-3-yloxy)-N,N,N-trimethylbut-2-yn-1-aminium
C10 H17 N2 O2
Binding Affinity Annotations 
IDSourceBinding Affinity
2CU BindingDB:  4MQT Ki: min: 3548, max: 9333 (nM) from 5 assay(s)
IC50: 3.16e+4 (nM) from 1 assay(s)
IXO BindingDB:  4MQT 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

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.032α = 90
b = 77.399β = 90
c = 163.822γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Revision History  (Full details and data files)

  • 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
  • Version 1.4: 2019-05-01
    Changes: Data collection, Structure summary
  • Version 1.5: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description