5K6W

Sidekick-1 immunoglobulin domains 1-5


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.5 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.202 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Molecular basis of sidekick-mediated cell-cell adhesion and specificity.

Goodman, K.M.Yamagata, M.Jin, X.Mannepalli, S.Katsamba, P.S.Ahlsen, G.Sergeeva, A.P.Honig, B.Sanes, J.R.Shapiro, L.

(2016) Elife 5: --

  • DOI: 10.7554/eLife.19058
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Sidekick (Sdk) 1 and 2 are related immunoglobulin superfamily cell adhesion proteins required for appropriate synaptic connections between specific subtypes of retinal neurons. Sdks mediate cell-cell adhesion with homophilic specificity that underlie ...

    Sidekick (Sdk) 1 and 2 are related immunoglobulin superfamily cell adhesion proteins required for appropriate synaptic connections between specific subtypes of retinal neurons. Sdks mediate cell-cell adhesion with homophilic specificity that underlies their neuronal targeting function. Here we report crystal structures of Sdk1 and Sdk2 ectodomain regions, revealing similar homodimers mediated by the four N-terminal immunoglobulin domains (Ig1-4), arranged in a horseshoe conformation. These Ig1-4 horseshoes interact in a novel back-to-back orientation in both homodimers through Ig1:Ig2, Ig1:Ig1 and Ig3:Ig4 interactions. Structure-guided mutagenesis results show that this canonical dimer is required for both Sdk-mediated cell aggregation (via trans interactions) and Sdk clustering in isolated cells (via cis interactions). Sdk1/Sdk2 recognition specificity is encoded across Ig1-4, with Ig1-2 conferring the majority of binding affinity and differential specificity. We suggest that competition between cis and trans interactions provides a novel mechanism to sharpen the specificity of cell-cell interactions.


    Organizational Affiliation

    Department of Systems Biology, Columbia University, New York, United States.,Howard Hughes Medical Institute, Columbia University, New York, United States.,Department of Medicine, Columbia University, New York, United States.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.,Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States.,Center for Brain Science, Harvard University, Cambridge, United States.,Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protein sidekick-1
A, B
481Mus musculusMutation(s): 0 
Gene Names: Sdk1
Find proteins for Q3UH53 (Mus musculus)
Go to UniProtKB:  Q3UH53
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A, B
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
FUC
Query on FUC

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Download CCD File 
A, B
ALPHA-L-FUCOSE
C6 H12 O5
SHZGCJCMOBCMKK-SXUWKVJYSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A, B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

Unit Cell:
Length (Å)Angle (°)
a = 70.140α = 90.00
b = 152.870β = 90.00
c = 158.970γ = 90.00
Software Package:
Software NamePurpose
iMOSFLMdata reduction
PHENIXrefinement
SCALAdata scaling
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-09-28
    Type: Initial release