1I4E

CRYSTAL STRUCTURE OF THE CASPASE-8/P35 COMPLEX

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.296 
  • R-Value Work: 0.236 

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This is version 1.3 of the entry. See complete history. 


Literature

Covalent inhibition revealed by the crystal structure of the caspase-8/p35 complex.

Xu, G., Cirilli, M., Huang, Y., Rich, R.L., Myszka, D.G., Wu, H.

(2001) Nature 410: 494-497

  • DOI: 10.1038/35068604
  • Primary Citation of Related Structures:  
    1I4E

  • PubMed Abstract: 

    • Apoptosis is a highly regulated process that is crucial for normal development and homeostasis of multicellular organisms. The p35 protein from baculoviruses effectively prevents apoptosis by its broad-spectrum caspase inhibition. Here we report the crys ...

    Apoptosis is a highly regulated process that is crucial for normal development and homeostasis of multicellular organisms. The p35 protein from baculoviruses effectively prevents apoptosis by its broad-spectrum caspase inhibition. Here we report the crystal structure of p35 in complex with human caspase-8 at 3.0 A resolution, and biochemical and mutagenesis studies based on the structural information. The structure reveals that the caspase is inhibited in the active site through a covalent thioester linkage to p35, which we confirmed by gel electrophoresis, hydroxylamine treatment and mass spectrometry experiments. The p35 protein undergoes dramatic conformational changes on cleavage by the caspase. The repositioning of the amino terminus of p35 into the active site of the caspase eliminates solvent accessibility of the catalytic dyad. This may be crucial for preventing hydrolysis of the thioester intermediate, which is supported by the abrogation of inhibitory activity through mutations at the N terminus of p35. The p35 protein also makes conserved contacts with the caspase outside the active-site region, providing the molecular basis for the broad-spectrum inhibitory activity of this protein. We demonstrate a new molecular mechanism of caspase inhibition, as well as protease inhibition in general.

    Organizational Affiliation: 

    Department of Biochemistry, Weill Medical College of Cornell University, New York, New York, 10021 USA



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Early 35 kDa protein A299Autographa californica nucleopolyhedrovirusMutation(s): 1 
Gene Names: P35
Find proteins for P08160 (Autographa californica nuclear polyhedrosis virus)
Explore P08160 
Go to UniProtKB:  P08160
Protein Feature View
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  • Reference Sequence
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(by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Caspase-8 B258Homo sapiensMutation(s): 0 
Gene Names: CASP8, MCH5
EC: 3.4.22.61
Find proteins for Q14790 (Homo sapiens)
Explore Q14790 
Go to UniProtKB:  Q14790
NIH Common Fund Data Resources
PHAROS:  Q14790
GTEx:  ENSG00000064012
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.296 
  • R-Value Work: 0.236 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 99.97α = 90
b = 117.34β = 90
c = 346.45γ = 90
Software Package:
Software NamePurpose
GLRFphasing
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-03-28
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2013-09-25
    Changes: Derived calculations