1QBA

BACTERIAL CHITOBIASE, GLYCOSYL HYDROLASE FAMILY 20


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.196 
  • R-Value Work: 0.139 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Bacterial chitobiase structure provides insight into catalytic mechanism and the basis of Tay-Sachs disease.

Tews, I.Perrakis, A.Oppenheim, A.Dauter, Z.Wilson, K.S.Vorgias, C.E.

(1996) Nat.Struct.Mol.Biol. 3: 638-648

  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Chitin, the second most abundant polysaccharide on earth, is degraded by chitinases and chitobiases. The structure of Serratia marcescens chitobiase has been refined at 1.9 A resolution. The mature protein is folded into four domains and its active s ...

    Chitin, the second most abundant polysaccharide on earth, is degraded by chitinases and chitobiases. The structure of Serratia marcescens chitobiase has been refined at 1.9 A resolution. The mature protein is folded into four domains and its active site is situated at the C-terminal end of the central (beta alpha)8-barrel. Based on the structure of the complex with the substrate disaccharide chitobiose, we propose an acid-base reaction mechanism, in which only one protein carboxylate acts as catalytic acid, while the nucleophile is the polar acetamido group of the sugar in a substrate-assisted reaction. The structural data lead to the hypothesis that the reaction proceeds with retention of anomeric configuration. The structure allows us to model the catalytic domain of the homologous hexosaminidases to give a structural rationale to pathogenic mutations that underlie Tay-Sachs and Sandhoff disease.


    Related Citations: 
    • N-Acetylglucosaminidase (Chitobiase) from Serratia Marcescens: Gene Sequence, and Protein Production and Purification in Escherichia Coli
      Tews, I.,Vincentelli, R.,Vorgias, C.E.
      (1996) Gene 170: 63
    • Cloning of the Gene Coding for Chitobiase of Serratia Marcescens
      Kless, H.,Sitrit, Y.,Chet, I.,Oppenheim, A.B.
      (1989) Mol.Gen.Genet. 217: 471
    • Tews, I.
      (1996) Serratia Marcescens Chitobiase --: --


    Organizational Affiliation

    European Molecular Biology Laboratory, Hamburg, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CHITOBIASE
A
858Serratia marcescensMutation(s): 0 
Gene Names: chb
EC: 3.2.1.52
Find proteins for Q54468 (Serratia marcescens)
Go to UniProtKB:  Q54468
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.196 
  • R-Value Work: 0.139 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 110.700α = 90.00
b = 99.900β = 90.00
c = 87.700γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PROLSQrefinement
PHASESphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-01-11
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance