Crystal structure of a human ependymin related protein

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.201 

wwPDB Validation   3D Report Full Report

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Structures of three ependymin-related proteins suggest their function as a hydrophobic molecule binder.

Park, J.K.Kim, K.Y.Sim, Y.W.Kim, Y.I.Kim, J.K.Lee, C.Han, J.Kim, C.U.Lee, J.E.Park, S.

(2019) IUCrJ 6: 729-739

  • DOI: https://doi.org/10.1107/S2052252519007668
  • Primary Citation of Related Structures:  
    6JL9, 6JLA, 6JLD

  • PubMed Abstract: 

    Ependymin was first discovered as a predominant protein in brain extracellular fluid in fish and was suggested to be involved in functions mostly related to learning and memory. Orthologous proteins to ependymin called ependymin-related proteins (EPDRs) have been found to exist in various tissues from sea urchins to humans, yet their functional role remains to be revealed. In this study, the structures of EPDR1 from frog, mouse and human were determined and analyzed. All of the EPDR1s fold into a dimer using a monomeric subunit that is mostly made up of two stacking antiparallel β-sheets with a curvature on one side, resulting in the formation of a deep hydrophobic pocket. All six of the cysteine residues in the monomeric subunit participate in the formation of three intramolecular disulfide bonds. Other interesting features of EPDR1 include two asparagine residues with glycosylation and a Ca 2+ -binding site. The EPDR1 fold is very similar to the folds of bacterial VioE and LolA/LolB, which also use a similar hydrophobic pocket for their respective functions as a hydrophobic substrate-binding enzyme and a lipoprotein carrier, respectively. A further fatty-acid binding assay using EPDR1 suggests that it indeed binds to fatty acids, presumably via this pocket. Additional interactome analysis of EPDR1 showed that EPDR1 interacts with insulin-like growth factor 2 receptor and flotillin proteins, which are known to be involved in protein and vesicle translocation.

  • Organizational Affiliation

    School of Systems Biomedical Science, Soongsil University, Seoul 06978, Republic of Korea.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Mammalian ependymin-related protein 1
A, B, C, D
198Homo sapiensMutation(s): 0 
Gene Names: EPDR1MERP1UCC1
UniProt & NIH Common Fund Data Resources
Find proteins for Q9UM22 (Homo sapiens)
Explore Q9UM22 
Go to UniProtKB:  Q9UM22
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9UM22
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.201 
  • Space Group: P 43
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.858α = 90
b = 55.858β = 90
c = 273.769γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

  • Released Date: 2019-07-10 
  • Deposition Author(s): Park, S.Y.

Funding OrganizationLocationGrant Number
National Research Foundation (Korea)Korea, Republic Of2016R1D1A1A09918187

Revision History  (Full details and data files)

  • Version 1.0: 2019-07-10
    Type: Initial release
  • Version 1.1: 2019-07-31
    Changes: Data collection, Database references