1U2H

X-ray Structure of the N-terminally truncated human APEP-1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.96 Å
  • R-Value Free: 0.172 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.161 

Starting Models: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

X-ray structure of engineered human Aortic Preferentially Expressed Protein-1 (APEG-1)

Manjasetty, B.A.Niesen, F.H.Scheich, C.Roske, Y.Gotz, F.Behlke, J.Sievert, V.Heinemann, U.Bussow, K.

(2005) BMC Struct Biol 5: 21-21

  • DOI: https://doi.org/10.1186/1472-6807-5-21
  • Primary Citation of Related Structures:  
    1U2H

  • PubMed Abstract: 

    Human Aortic Preferentially Expressed Protein-1 (APEG-1) is a novel specific smooth muscle differentiation marker thought to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). Good quality crystals that were suitable for X-ray crystallographic studies were obtained following the truncation of the 14 N-terminal amino acids of APEG-1, a region predicted to be disordered. The truncated protein (termed DeltaAPEG-1) consists of a single immunoglobulin (Ig) like domain which includes an Arg-Gly-Asp (RGD) adhesion recognition motif. The RGD motif is crucial for the interaction of extracellular proteins and plays a role in cell adhesion. The X-ray structure of DeltaAPEG-1 was determined and was refined to sub-atomic resolution (0.96 A). This is the best resolution for an immunoglobulin domain structure so far. The structure adopts a Greek-key beta-sandwich fold and belongs to the I (intermediate) set of the immunoglobulin superfamily. The residues lying between the beta-sheets form a hydrophobic core. The RGD motif folds into a 310 helix that is involved in the formation of a homodimer in the crystal which is mainly stabilized by salt bridges. Analytical ultracentrifugation studies revealed a moderate dissociation constant of 20 microM at physiological ionic strength, suggesting that APEG-1 dimerisation is only transient in the cell. The binding constant is strongly dependent on ionic strength. Our data suggests that the RGD motif might play a role not only in the adhesion of extracellular proteins but also in intracellular protein-protein interactions. However, it remains to be established whether the rather weak dimerisation of APEG-1 involving this motif is physiologically relevant.


  • Organizational Affiliation

    Protein Structure Factory, c/o BESSY GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany. babu@bnl.gov


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Aortic preferentially expressed protein 199Homo sapiensMutation(s): 0 
Gene Names: Arotic Preferentially Expressed Gene 1
EC: 2.7.11.1
UniProt & NIH Common Fund Data Resources
Find proteins for Q15772 (Homo sapiens)
Explore Q15772 
Go to UniProtKB:  Q15772
PHAROS:  Q15772
GTEx:  ENSG00000072195 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ15772
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.96 Å
  • R-Value Free: 0.172 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.161 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 81.541α = 90
b = 25.522β = 104.59
c = 42.544γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-07-05
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-10-25
    Changes: Data collection, Database references, Refinement description