1S4V

The 2.0 A crystal structure of the KDEL-tailed cysteine endopeptidase functioning in programmed cell death of Ricinus communis endosperm


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.181 

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This is version 1.3 of the entry. See complete history


Literature

The 2.0 A crystal structure and substrate specificity of the KDEL-tailed cysteine endopeptidase functioning in programmed cell death of Ricinus communis endosperm.

Than, M.E.Helm, M.Simpson, D.J.Lottspeich, F.Huber, R.Gietl, C.

(2004) J Mol Biol 336: 1103-1116

  • DOI: 10.1016/j.jmb.2003.12.075
  • Primary Citation of Related Structures:  
    1S4V

  • PubMed Abstract: 
  • In the senescing endosperm of germinating castor bean (Ricinus communis) a special organelle (the ricinosome) releases a papain-type cysteine endopeptidase (CysEP) during the final stages of cellular disintegration. Protein cleavage sites for the Ricinus CysEP were determined with fluorogenic peptides (Abz-Xaa-Arg-/-Gln-Gln-Tyr(NO2)-Asp) ...

    In the senescing endosperm of germinating castor bean (Ricinus communis) a special organelle (the ricinosome) releases a papain-type cysteine endopeptidase (CysEP) during the final stages of cellular disintegration. Protein cleavage sites for the Ricinus CysEP were determined with fluorogenic peptides (Abz-Xaa-Arg-/-Gln-Gln-Tyr(NO2)-Asp). The highest kcat/Km values were obtained with neutral amino acid residues with large aliphatic and non-polar (Leu, Val, Ile, Met) or aromatic (Phe, Tyr, Trp) side-chains. A second series (Abz-Leu-Xaa-/Gln-Pro-Tyr(NO2)-Asp) was evaluated. Based on these results, the covalent binding inhibitor H-D-Val-Leu-Lys-chloromethylketone (CMK) was chosen as substrate analogue for replacement in the catalytic site. Unusually, CysEP cleaved beta-casein N and C-terminal to the amino acid proline. CysEP was crystallized, its structure was solved by molecular replacement at 2.0 A resolution and refined to a R-factor of 18.1% (Rfree=22.6%). The polypeptide chain folds as in papain into two domains divided by the active site cleft, an elongated surface depression harboring the active site. The non-primed specificity subsites of the proteinase are clearly defined by the H-D-Val-Leu-Lys-CMK-inhibitor covalently bound to the active site. The absence of the occluding loop, which blocks the active site of exopeptidases at the C-terminal side of the scissile bond, identifies CysEP as an endopeptidase. The more open pocket of the Ricinus CysEP correlates with the extended variety of substrate amino acid residues accommodated by this enzyme, including even proline at the P1 and P1' positions. This may allow the enzyme to attack a greater variety of proteins during programmed cell death.


    Organizational Affiliation

    Max-Plank-Institut für Biochemie, Abteilung Strukturforschung, D-82152 Martinsried, Germany. than@biochem.mpg.de



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
cysteine endopeptidaseA, B229Ricinus communisMutation(s): 0 
Gene Names: CYSEP
EC: 3.4.22
UniProt
Find proteins for O65039 (Ricinus communis)
Explore O65039 
Go to UniProtKB:  O65039
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO65039
Protein Feature View
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  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
DVA-LEU-LYS-0QE peptideC, D4Ricinus communisMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
E [auth A]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.181 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 36.448α = 90
b = 68.162β = 90
c = 163.78γ = 90
Software Package:
Software NamePurpose
CNSrefinement
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: 2004-03-16
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Atomic model, Database references, Derived calculations, Non-polymer description, Structure summary, Version format compliance
  • Version 1.3: 2012-12-12
    Changes: Other