6BK9

Crystal Structure of Squid Arrestin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.342 
  • R-Value Work: 0.292 
  • R-Value Observed: 0.295 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

A Novel Polar Core and Weakly Fixed C-Tail in Squid Arrestin Provide New Insight into Interaction with Rhodopsin.

Bandyopadhyay, A.Van Eps, N.Eger, B.T.Rauscher, S.Yedidi, R.S.Moroni, T.West, G.M.Robinson, K.A.Griffin, P.R.Mitchell, J.Ernst, O.P.

(2018) J Mol Biol 430: 4102-4118

  • DOI: 10.1016/j.jmb.2018.08.009
  • Primary Citation of Related Structures:  
    6BK9

  • PubMed Abstract: 
  • Photoreceptors of the squid Loligo pealei contain a G-protein-coupled receptor (GPCR) signaling system that activates phospholipase C in response to light. Analogous to the mammalian visual system, signaling of the photoactivated GPCR rhodopsin is terminated by binding of squid arrestin (sArr) ...

    Photoreceptors of the squid Loligo pealei contain a G-protein-coupled receptor (GPCR) signaling system that activates phospholipase C in response to light. Analogous to the mammalian visual system, signaling of the photoactivated GPCR rhodopsin is terminated by binding of squid arrestin (sArr). sArr forms a light-dependent, high-affinity complex with squid rhodopsin, which does not require prior receptor phosphorylation for interaction. This is at odds with classical mammalian GPCR desensitization where an agonist-bound phosphorylated receptor is needed to break stabilizing constraints within arrestins, the so-called "three-element interaction" and "polar core" network, before a stable receptor-arrestin complex can be established. Biophysical and mass spectrometric analysis of the squid rhodopsin-arrestin complex indicates that in contrast to mammalian arrestins, the sArr C-tail is not involved in a stable three-element interaction. We determined the crystal structure of C-terminally truncated sArr that adopts a basal conformation common to arrestins and is stabilized by a series of weak but novel polar core interactions. Unlike mammalian arrestin-1, deletion of the sArr C-tail does not influence kinetic properties of complex formation of sArr with the receptor. Hydrogen-deuterium exchange studies revealed the footprint of the light-activated rhodopsin on sArr. Furthermore, double electron-electron resonance spectroscopy experiments provide evidence that receptor-bound sArr adopts a conformation different from the one known for arrestin-1 and molecular dynamics simulations reveal the residues that account for the weak three-element interaction. Insights gleaned from studying this system add to our general understanding of GPCR-arrestin interaction.


    Organizational Affiliation

    Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada. Electronic address: oliver.ernst@utoronto.ca.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Visual arrestinA380Doryteuthis pealeiiMutation(s): 0 
UniProt
Find proteins for Q963B5 (Doryteuthis pealeii)
Explore Q963B5 
Go to UniProtKB:  Q963B5
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download Ideal Coordinates CCD File 
B [auth A]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.342 
  • R-Value Work: 0.292 
  • R-Value Observed: 0.295 
  • Space Group: P 65 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 103.508α = 90
b = 103.508β = 90
c = 153.772γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
MOSFLMdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

View Full Validation Report




Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Government of CanadaCanadaCanada Research Excellence Chair

Revision History  (Full details and data files)

  • Version 1.0: 2018-09-19
    Type: Initial release
  • Version 1.1: 2018-10-24
    Changes: Data collection, Database references