2Z37

Crystal structure of Brassica juncea chitinase catalytic module (Bjchi3)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.53 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.185 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal structures of a family 19 chitinase from Brassica juncea show flexibility of binding cleft loops

Ubhayasekera, W.Tang, C.M.Ho, S.W.T.Berglund, G.Bergfors, T.Chye, M.-L.Mowbray, S.L.

(2007) Febs J. 274: 3695-3703

  • DOI: 10.1111/j.1742-4658.2007.05906.x
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Brassica juncea chitinase is an endo-acting, pathogenesis-related protein that is classified into glycoside hydrolase family 19, with highest homology (50-60%) in its catalytic domain to class I plant chitinases. Here we report X-ray structures of th ...

    Brassica juncea chitinase is an endo-acting, pathogenesis-related protein that is classified into glycoside hydrolase family 19, with highest homology (50-60%) in its catalytic domain to class I plant chitinases. Here we report X-ray structures of the chitinase catalytic domain from wild-type (apo, as well as with chloride ions bound) and a Glu234Ala mutant enzyme, solved by molecular replacement and refined at 1.53, 1.8 and 1.7 A resolution, respectively. Confirming our earlier mutagenesis studies, the active-site residues are identified as Glu212 and Glu234. Glu212 is believed to be the catalytic acid in the reaction, whereas Glu234 is thought to have a dual role, both activating a water molecule in its attack on the anomeric carbon, and stabilizing the charged intermediate. The molecules in the various structures differ significantly in the conformation of a number of loops that border the active-site cleft. The differences suggest an opening and closing of the enzyme during the catalytic cycle. Chitin is expected to dock first near Glu212, which will protonate it. Conformational changes then bring Glu234 closer, allowing it to assist in the following steps. These observations provide important insights into catalysis in family 19 chitinases.


    Organizational Affiliation

    Department of Molecular Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Chitinase
A, B, C, D
244Brassica junceaMutation(s): 0 
Find proteins for Q9SQF7 (Brassica juncea)
Go to UniProtKB:  Q9SQF7
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.53 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.185 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 51.249α = 79.34
b = 61.821β = 89.52
c = 75.359γ = 88.90
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
REFMACrefinement
MOLREPphasing
SCALEPACKdata scaling
DENZOdata reduction
ADSCdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-06-19
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description