Biological Assembly 1  

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

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 Pseudo Symmetry: Cyclic - C2  (3D View)
Pseudo Stoichiometry: Homo 2-mer - A2 

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

Macromolecule Content

• Total Structure Weight: 51.85 kDa 
• Atom Count: 4155 
• Modelled Residue Count: 443 
• Deposited Residue Count: 456 
• Unique protein chains: 2

4AQA

CRYSTAL STRUCTURE OF DEAFNESS ASSOCIATED MUTANT MOUSE CADHERIN-23 EC1- 2D124G AND PROTOCADHERIN-15 EC1-2 FORM I

• PDB DOI: 10.2210/pdb4AQA/pdb

• Classification: CELL ADHESION
• Organism(s): Mus musculus
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2012-04-15 Released: 2012-11-07 
• Deposition Author(s): Sotomayor, M., Weihofen, W., Gaudet, R., Corey, D.P.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.96 Å
• R-Value Free: 0.228 
• R-Value Work: 0.178 
• R-Value Observed: 0.180 

Literature

Structure of a Force-Conveying Cadherin Bond Essential for Inner-Ear Mechanotransduction

Sotomayor, M., Weihofen, W., Gaudet, R., Corey, D.P.

(2012) Nature 492: 128

• PubMed: 23135401 
• DOI: 10.1038/nature11590
• Primary Citation of Related Structures:  
  4APX, 4AQ8, 4AQA, 4AQE, 4AXW


• PubMed Abstract: 
  

Hearing and balance use hair cells in the inner ear to transform mechanical stimuli into electrical signals. Mechanical force from sound waves or head movements is conveyed to hair-cell transduction channels by tip links, fine filaments formed by two atypical cadherins known as protocadherin 15 and cadherin 23 (refs 4, 5). These two proteins are involved in inherited deafness and feature long extracellular domains that interact tip-to-tip in a Ca(2+)-dependent manner. However, the molecular architecture of this complex is unknown. Here we combine crystallography, molecular dynamics simulations and binding experiments to characterize the protocadherin 15-cadherin 23 bond. We find a unique cadherin interaction mechanism, in which the two most amino-terminal cadherin repeats (extracellular cadherin repeats 1 and 2) of each protein interact to form an overlapped, antiparallel heterodimer. Simulations predict that this tip-link bond is mechanically strong enough to resist forces in hair cells. In addition, the complex is shown to become unstable in response to Ca(2+) removal owing to increased flexure of Ca(2+)-free cadherin repeats. Finally, we use structures and biochemical measurements to study the molecular mechanisms by which deafness mutations disrupt tip-link function. Overall, our results shed light on the molecular mechanics of hair-cell sensory transduction and on new interaction mechanisms for cadherins, a large protein family implicated in tissue and organ morphogenesis, neural connectivity and cancer.

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Organizational Affiliation: 

Howard Hughes Medical Institute and Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
CADHERIN-23	A	214	Mus musculus	Mutation(s): 1  Gene Names: Cdh23
UniProt & NIH Common Fund Data Resources
Find proteins for Q99PF4 (Mus musculus) Explore Q99PF4  Go to UniProtKB:  Q99PF4
IMPC:  MGI:1890219

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTOCADHERIN-15	B	242	Mus musculus	Mutation(s): 0  Gene Names: Pcdh15
UniProt & NIH Common Fund Data Resources
Find proteins for Q99PJ1 (Mus musculus) Explore Q99PJ1  Go to UniProtKB:  Q99PJ1
IMPC:  MGI:1891428

Small Molecules

Ligands 4 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
MES	G [auth A]	2-(N-MORPHOLINO)-ETHANESULFONIC ACID C6 H13 N O4 S SXGZJKUKBWWHRA-UHFFFAOYSA-N
CA	C [auth A], D [auth A], E [auth A], F [auth A], I [auth B], J [auth B], K [auth B]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N
K	L [auth B]	POTASSIUM ION K NPYPAHLBTDXSSS-UHFFFAOYSA-N
CL	H [auth A]	CHLORIDE ION Cl VEXZGXHMUGYJMC-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.96 Å
• R-Value Free: 0.228 
• R-Value Work: 0.178 
• R-Value Observed: 0.180 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 173.293	α = 90
b = 40.506	β = 102.86
c = 84.629	γ = 90

Software Package:

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

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2012-04-15 
• Released Date: 2012-11-07 
Deposition Author(s): Sotomayor, M., Weihofen, W., Gaudet, R., Corey, D.P.

Revision History  

• Version 1.0: 2012-11-07
  Type: Initial release
  
• Version 1.1: 2012-11-21
  Changes: Database references
• Version 1.2: 2012-12-12
  Changes: Database references