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 1.2 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: https://doi.org/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). 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.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Visual arrestin380Doryteuthis pealeiiMutation(s): 0 
UniProt
Find proteins for Q963B5 (Doryteuthis pealeii)
Explore Q963B5 
Go to UniProtKB:  Q963B5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ963B5
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download Ideal Coordinates CCD File 
B [auth A]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
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
  • Version 1.2: 2023-10-04
    Changes: Data collection, Database references, Refinement description