3NKF

Crystal structure of human ligand-free mature caspase-6 with intersubunit linker attached


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.216 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Substrate-Induced Conformational Changes Occur in All Cleaved Forms of Caspase-6.

Vaidya, S.Velazquez-Delgado, E.M.Abbruzzese, G.Hardy, J.A.

(2011) J.Mol.Biol. 406: 75-91

  • DOI: 10.1016/j.jmb.2010.11.031

  • PubMed Abstract: 
  • Caspase-6 is an apoptotic cysteine protease that also governs disease progression in Huntington's and Alzheimer's diseases. Caspase-6 is of great interest as a target for treatment of these neurodegenerative diseases; however, the molecular basis of ...

    Caspase-6 is an apoptotic cysteine protease that also governs disease progression in Huntington's and Alzheimer's diseases. Caspase-6 is of great interest as a target for treatment of these neurodegenerative diseases; however, the molecular basis of caspase-6 function and regulation remains poorly understood. In the recently reported structure of caspase-6, the 60's and 130's helices at the base of the substrate-binding groove extend upward, in a conformation entirely different from that of any other caspase. Presently, the central question about caspase-6 structure and function is whether the extended conformation is the catalytically competent conformation or whether the extended helices must undergo a large conformational rearrangement in order to bind substrate. We have generated a series of caspase-6 cleavage variants, including a novel constitutively two-chain form, and determined crystal structures of caspase-6 with and without the intersubunit linker. This series allows evaluation of the role of the prodomain and intersubunit linker on caspase-6 structure and function before and after substrate binding. Caspase-6 is inherently more stable than closely related caspases. Cleaved caspase-6 with both the prodomain and the linker present is the most stable, indicating that these two regions act in concert to increase stability, but maintain the extended conformation in the unliganded state. Moreover, these data suggest that caspase-6 undergoes a significant conformational change upon substrate binding, adopting a structure that is more like canonical caspases.


    Organizational Affiliation

    Department of Chemistry, University of Massachusetts Amherst, 104 Lederle Graduate Research Tower,710 North Pleasant Street, Amherst, MA 01003, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Caspase-6
A, B, C, D
277Homo sapiensMutation(s): 0 
Gene Names: CASP6 (MCH2)
EC: 3.4.22.59
Find proteins for P55212 (Homo sapiens)
Go to Gene View: CASP6
Go to UniProtKB:  P55212
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.216 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 63.290α = 90.00
b = 90.814β = 91.04
c = 85.912γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PHASESphasing
REFMACrefinement
HKL-2000data collection
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-12-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance