2H7W

Crystal structure of Chagasin, the endogenous cysteine-protease inhibitor from Trypanosoma cruzi


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal structure of chagasin, the endogenous cysteine-protease inhibitor from Trypanosoma cruzi.

Figueiredo da Silva, A.A.Vieira, L.C.Krieger, M.A.Goldenberg, S.Zanchin, N.I.Guimaraes, B.G.

(2007) J.Struct.Biol. 157: 416-423

  • DOI: 10.1016/j.jsb.2006.07.017

  • PubMed Abstract: 
  • Trypanosoma cruzi chagasin belongs to a recently discovered family of cysteine protease inhibitors found in lower eukaryotes and prokaryotes but not in mammals. Chagasin binds tightly to cruzain, the major lysosomal T. cruzi cysteine protease, involv ...

    Trypanosoma cruzi chagasin belongs to a recently discovered family of cysteine protease inhibitors found in lower eukaryotes and prokaryotes but not in mammals. Chagasin binds tightly to cruzain, the major lysosomal T. cruzi cysteine protease, involved with infectivity and survival of the parasite in mammalian host cells. In the scope of a project to characterize proteins diferentially expressed during T. cruzi metacyclogenesis, we have determined the crystal structure of chagasin, which is now the first X-ray structure of a chagasin-like cysteine protease inhibitor to be reported. The structure was solved by the SIRAS method and refined at 1.7A resolution and a comparison with the two NMR structures available revealed some differences in the loops involved in binding to cysteine proteases. The highly flexible loop 4 could be entirely modeled and residues 29-33 from loop 2 form a 3(10)-helix structure that may be important to stabilize the loop conformation. Chagasin crystal structure was docked to the highest resolution structure available of cruzain and a model of chagasin-cruzain interaction was analyzed. The knowledge of the chagasin crystal structure may contribute to the elucidation of the molecular mechanism involved in the inhibition of cruzain and other T. cruzi cysteine proteases.


    Organizational Affiliation

    Centro de Biologia Molecular Estrutural, Laboratório Nacional de Luz Síncrotron, LNLS, P.O. Box 6192, CEP 13084-971, Campinas SP, Brazil.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Chagasin
A, B
131Trypanosoma cruziMutation(s): 0 
Gene Names: cha
Find proteins for Q966X9 (Trypanosoma cruzi)
Go to UniProtKB:  Q966X9
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.205 
  • Space Group: P 31 1 2
Unit Cell:
Length (Å)Angle (°)
a = 48.779α = 90.00
b = 48.779β = 90.00
c = 183.602γ = 120.00
Software Package:
Software NamePurpose
MAR345data collection
CCP4data scaling
MOSFLMdata reduction
REFMACrefinement
SHARPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-10-10
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-18
    Type: Refinement description