3W4R

Crystal structure of an insect chitinase from the Asian corn borer, Ostrinia furnacalis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.159 
  • R-Value Work: 0.147 
  • R-Value Observed: 0.147 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural characteristics of an insect group I chitinase, an enzyme indispensable to moulting

Chen, L.Liu, T.Zhou, Y.Chen, Q.Shen, X.Yang, Q.

(2014) Acta Crystallogr D Biol Crystallogr 70: 932-942

  • DOI: 10.1107/S1399004713033841
  • Primary Citation of Related Structures:  
    3W4R, 3WKZ, 3WL0, 3WL1

  • PubMed Abstract: 
  • Insects possess a greater number of chitinases than any other organisms. This work is the first report of unliganded and oligosaccharide-complexed crystal structures of the insect chitinase OfChtI from Ostrinia furnacalis, which is essential to moult ...

    Insects possess a greater number of chitinases than any other organisms. This work is the first report of unliganded and oligosaccharide-complexed crystal structures of the insect chitinase OfChtI from Ostrinia furnacalis, which is essential to moulting. The obtained crystal structures were solved at resolutions between 1.7 and 2.2 Å. A structural comparison with other chitinases revealed that OfChtI contains a long substrate-binding cleft similar to the bacterial chitinase SmChiB from Serratia marcescens. However, unlike the exo-acting SmChiB, which has a blocked and tunnel-like cleft, OfChtI possesses an open and groove-like cleft. The complexed structure of the catalytic domain of OfChtI (OfChtI-CAD) with (GlcNAc)2/3 indicates that the reducing sugar at subsite -1 is in an energetically unfavoured `boat' conformation, a state that possibly exists just before the completion of catalysis. Because OfChtI is known to act from nonreducing ends, (GlcNAc)3 would be a hydrolysis product of (GlcNAc)6, suggesting that OfChtI possesses an endo enzymatic activity. Furthermore, a hydrophobic plane composed of four surface-exposed aromatic residues is adjacent to the entrance to the substrate-binding cleft. Mutations of these residues greatly impair the chitin-binding activity, indicating that this hydrophobic plane endows OfChtI-CAD with the ability to anchor chitin. This work reveals the unique structural characteristics of an insect chitinase.


    Organizational Affiliation

    School of Life Science and Biotechnology, Dalian University of Technology, 2 Linggong Road, Dalian, Liaoning 116024, People's Republic of China.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ChitinaseA554Ostrinia furnacalisMutation(s): 0 
EC: 3.2.1.14
Find proteins for Q2V6H4 (Ostrinia furnacalis)
Explore Q2V6H4 
Go to UniProtKB:  Q2V6H4
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download CCD File 
A
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.159 
  • R-Value Work: 0.147 
  • R-Value Observed: 0.147 
  • Space Group: P 65
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 93.761α = 90
b = 93.761β = 90
c = 121.964γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
PHASERphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-02-12
    Type: Initial release
  • Version 1.1: 2014-05-07
    Changes: Database references
  • Version 1.2: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary