3H1P

Mature Caspase-7 I213A with DEVD-CHO inhibitor bound to active site


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.61 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.202 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.7 of the entry. See complete history


Literature

L2' loop is critical for caspase-7 active site formation.

Witkowski, W.A.Hardy, J.A.

(2009) Protein Sci 18: 1459-1468

  • DOI: https://doi.org/10.1002/pro.151
  • Primary Citation of Related Structures:  
    3H1P

  • PubMed Abstract: 

    The active sites of caspases are composed of four mobile loops. A loop (L2) from one half of the dimer interacts with a loop (L2') from the other half of the dimer to bind substrate. In an inactive form, the two L2' loops form a cross-dimer hydrogen-bond network over the dimer interface. Although the L2' loop has been implicated as playing a central role in the formation of the active-site loop bundle, its precise role in catalysis has not been shown. A detailed understanding of the active and inactive conformations is essential to control the caspase function. We have interrogated the contributions of the residues in the L2' loop to catalytic function and enzyme stability. In wild-type and all mutants, active-site binding results in substantial stabilization of the complex. One mutation, P214A, is significantly destabilized in the ligand-free conformation, but is as stable as wild type when bound to substrate, indicating that caspase-7 rests in different conformations in the absence and presence of substrate. Residues K212 and I213 in the L2' loop are shown to be essential for substrate-binding and thus proper catalytic function of the caspase. In the crystal structure of I213A, the void created by side-chain deletion is compensated for by rearrangement of tyrosine 211 to fill the void, suggesting that the requirements of substrate-binding are sufficiently strong to induce the active conformation. Thus, although the L2' loop makes no direct contacts with substrate, it is essential for buttressing the substrate-binding groove and is central to native catalytic efficiency.


  • Organizational Affiliation

    Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Caspase-7
A, B
260Homo sapiensMutation(s): 1 
Gene Names: CASP7MCH3
EC: 3.4.22.60
UniProt & NIH Common Fund Data Resources
Find proteins for P55210 (Homo sapiens)
Explore P55210 
Go to UniProtKB:  P55210
PHAROS:  P55210
GTEx:  ENSG00000165806 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP55210
Sequence Annotations
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  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
N-ACETYL-L-ALPHA-ASPARTYL-L-ALPHA-GLUTAMYL-N-[(2S)-1-CARBOXY-3-HYDROXYPROPAN-2-YL]-L-VALINAMIDE
C, D
5Homo sapiensMutation(s): 0 
Sequence Annotations
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  • Reference Sequence
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.61 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.202 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 89.347α = 90
b = 89.347β = 90
c = 186.101γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
REFMACrefinement
PDB_EXTRACTdata extraction
CrystalCleardata collection

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-06-30
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.2: 2011-10-05
    Changes: Structure summary
  • Version 1.3: 2013-02-27
    Changes: Other
  • Version 1.4: 2017-11-01
    Changes: Refinement description
  • Version 1.5: 2021-10-13
    Changes: Database references, Derived calculations
  • Version 1.6: 2023-09-06
    Changes: Data collection, Refinement description
  • Version 1.7: 2023-11-22
    Changes: Data collection