Biological Assembly 1  

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: 140.7 kDa 
• Atom Count: 8,913 
• Modelled Residue Count: 1,068 
• Deposited Residue Count: 1,230 
• Unique protein chains: 1

 5K5S

Crystal structure of the active form of human calcium-sensing receptor extracellular domain

• PDB DOI: 10.2210/pdb5K5S/pdb

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


• Deposited: 2016-05-23 Released: 2016-08-03 
• Deposition Author(s): Geng, Y., Mosyak, L., Kurinov, I., Zuo, H., Sturchler, E., Cheng, T.C., Subramanyam, P., Brown, A.P., Brennan, S.C., Mun, H.-C., Bush, M., Chen, Y., Nguyen, T., Cao, B., Chang, D., Quick, M., Conigrave, A., Colecraft, H.M., McDonald, P., Fan, Q.R.
• Funding Organization(s): American Heart Association, National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.60 Å
• R-Value Free: 0.222 
• R-Value Work: 0.211 
• R-Value Observed: 0.212 

Literature

Structural mechanism of ligand activation in human calcium-sensing receptor.

Geng, Y., Mosyak, L., Kurinov, I., Zuo, H., Sturchler, E., Cheng, T.C., Subramanyam, P., Brown, A.P., Brennan, S.C., Mun, H.C., Bush, M., Chen, Y., Nguyen, T.X., Cao, B., Chang, D.D., Quick, M., Conigrave, A.D., Colecraft, H.M., McDonald, P., Fan, Q.R.

(2016) Elife 5

• PubMed: 27434672 
• DOI: 10.7554/eLife.13662
• Primary Citation of Related Structures:  
  5K5S, 5K5T


• PubMed Abstract: 
  

Human calcium-sensing receptor (CaSR) is a G-protein-coupled receptor (GPCR) that maintains extracellular Ca(2+) homeostasis through the regulation of parathyroid hormone secretion. It functions as a disulfide-tethered homodimer composed of three main domains, the Venus Flytrap module, cysteine-rich domain, and seven-helix transmembrane region. Here, we present the crystal structures of the entire extracellular domain of CaSR in the resting and active conformations. We provide direct evidence that L-amino acids are agonists of the receptor. In the active structure, L-Trp occupies the orthosteric agonist-binding site at the interdomain cleft and is primarily responsible for inducing extracellular domain closure to initiate receptor activation. Our structures reveal multiple binding sites for Ca(2+) and PO4(3-) ions. Both ions are crucial for structural integrity of the receptor. While Ca(2+) ions stabilize the active state, PO4(3-) ions reinforce the inactive conformation. The activation mechanism of CaSR involves the formation of a novel dimer interface between subunits.

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Organizational Affiliation: 

Department of Pathology and Cell Biology, Columbia University, New York, United States.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Extracellular calcium-sensing receptor	A, B	615	Homo sapiens	Mutation(s): 3  Gene Names: CASR, GPRC2A, PCAR1
UniProt & NIH Common Fund Data Resources
Find proteins for P41180 (Homo sapiens) Explore P41180  Go to UniProtKB:  P41180
PHAROS:  P41180

Small Molecules

Ligands 4 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
NAG	J [auth A], K [auth A], L [auth A], M [auth A], U [auth B]	2-acetamido-2-deoxy-beta-D-glucopyranose C8 H15 N O6 OVRNDRQMDRJTHS-FMDGEEDCSA-N
TRP	C [auth A], O [auth B]	TRYPTOPHAN C11 H12 N2 O2 QIVBCDIJIAJPQS-VIFPVBQESA-N
PO4	D [auth A], E [auth A], P [auth B], Q [auth B]	PHOSPHATE ION O4 P NBIIXXVUZAFLBC-UHFFFAOYSA-K
CA	F [auth A], G [auth A], H [auth A], I [auth A], N [auth A], R [auth B], S [auth B], T [auth B]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.60 Å
• R-Value Free: 0.222 
• R-Value Work: 0.211 
• R-Value Observed: 0.212 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 107.66	α = 90
b = 127.45	β = 108.72
c = 146.77	γ = 90

Software Package:

Software Name	Purpose
BUSTER	refinement
XDS	data reduction
Aimless	data scaling
PHASER	phasing

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2016-08-03 
Deposition Author(s): Geng, Y., Mosyak, L., Kurinov, I., Zuo, H., Sturchler, E., Cheng, T.C., Subramanyam, P., Brown, A.P., Brennan, S.C., Mun, H.-C., Bush, M., Chen, Y., Nguyen, T., Cao, B., Chang, D., Quick, M., Conigrave, A., Colecraft, H.M., McDonald, P., Fan, Q.R.

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Funding Organization	Location	Grant Number
American Heart Association	United States	15GRNT25420002
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	R01GM112973

Revision History  

• Version 1.0: 2016-08-03
  Type: Initial release
  
• Version 1.1: 2016-08-24
  Changes: Data collection
• Version 1.2: 2017-09-20
  Changes: Author supporting evidence, Derived calculations
• Version 1.3: 2019-12-25
  Changes: Author supporting evidence
• Version 1.4: 2020-07-29
  Type: Remediation
  Reason: Carbohydrate remediation
  Changes: Data collection, Derived calculations, Structure summary