Structure of jack bean chitinase

Acta Crystallogr D Biol Crystallogr. 2000 Sep;56(Pt 9):1096-9. doi: 10.1107/s090744490000857x.


The structure of jack bean chitinase was solved at 1.8 A resolution by molecular replacement. It is an alpha-helical protein with three disulfide bridges. The active site is related in structure to animal and viral lysozymes. However, unlike in lysozyme, the architecture of the active site suggests a single-step cleavage. According to this mechanism, Glu68 is the proton donor and Glu90 assists in the reaction by moving towards the substrate and recruiting a water molecule that acts as the nucleophile. In this model, a water molecule was found in contact with Glu90 O(epsilon1) and Thr119 O(gamma) at a distance of 3.0 and 2.8 A, respectively. The model is in accordance with the observed inversion mechanism.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Chickens
  • Chitinases / chemistry*
  • Chitinases / isolation & purification
  • Crystallography, X-Ray
  • Egg Proteins / chemistry
  • Fabaceae / enzymology*
  • Hordeum / enzymology
  • Hydrogen Bonding
  • Molecular Sequence Data
  • Muramidase / chemistry
  • Plant Proteins / chemistry*
  • Plant Proteins / isolation & purification
  • Plants, Medicinal*
  • Protein Conformation
  • Protein Structure, Secondary
  • Seeds / enzymology
  • Sequence Homology, Amino Acid
  • Water / chemistry


  • Egg Proteins
  • Plant Proteins
  • Water
  • Chitinases
  • Muramidase

Associated data

  • PDB/1DXJ