1SC1

Crystal structure of an active-site ligand-free form of the human caspase-1 C285A mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.231 
  • R-Value Observed: 0.235 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystal structures of a ligand-free and malonate-bound human caspase-1: implications for the mechanism of substrate binding.

Romanowski, M.J.Scheer, J.M.O'Brien, T.McDowell, R.S.

(2004) Structure 12: 1361-1371

  • DOI: 10.1016/j.str.2004.05.010
  • Primary Citation of Related Structures:  
    1SC4, 1SC3, 1SC1

  • PubMed Abstract: 
  • Caspase-1, a mediator of the posttranslational processing of IL-1beta and IL-18, requires an aspartic acid in the P1 position of its substrates. The mechanisms of caspase-1 activation remain poorly understood despite numerous structures of the enzyme complexed with aspartate-based inhibitors ...

    Caspase-1, a mediator of the posttranslational processing of IL-1beta and IL-18, requires an aspartic acid in the P1 position of its substrates. The mechanisms of caspase-1 activation remain poorly understood despite numerous structures of the enzyme complexed with aspartate-based inhibitors. Here we report a crystal structure of ligand-free caspase-1 that displays dramatic rearrangements of loops defining the active site to generate a closed conformation that is incompatible with substrate binding. A structure of the enzyme complexed with malonate shows the protein in its open (active-site ligand-bound) conformation in which malonate reproduces the hydrogen bonding network observed in structures with covalent inhibitors. These results illustrate the essential function of the obligatory aspartate recognition element that opens the active site of caspase-1 to substrates and may be the determinant responsible for the conformational changes between ligand-free and -bound forms of the enzyme, and suggest a new approach for identifying novel aspartic acid mimetics.


    Organizational Affiliation

    Department of Structural Biology, Sunesis Pharmaceuticals, Inc., 341 Oyster Point Boulevard, South San Francisco, California 94080, USA. romanom@sunesis.com



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Interleukin-1 beta convertaseA178Homo sapiensMutation(s): 1 
Gene Names: CASP1IL1BCIL1BCE
EC: 3.4.22.36
Find proteins for P29466 (Homo sapiens)
Explore P29466 
Go to UniProtKB:  P29466
NIH Common Fund Data Resources
PHAROS:  P29466
Protein Feature View
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Interleukin-1 beta convertaseB88Homo sapiensMutation(s): 0 
Gene Names: CASP1IL1BCIL1BCE
EC: 3.4.22.36
Find proteins for P29466 (Homo sapiens)
Explore P29466 
Go to UniProtKB:  P29466
NIH Common Fund Data Resources
PHAROS:  P29466
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download Ideal Coordinates CCD File 
C [auth B]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.231 
  • R-Value Observed: 0.235 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 71.782α = 90
b = 71.782β = 90
c = 118.451γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
CrystalCleardata reduction
d*TREKdata scaling
AMoREphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-08-10
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2020-02-12
    Changes: Data collection, Derived calculations