3ZXJ

Engineering the active site of a GH43 glycoside hydrolase generates a biotechnologically significant enzyme that displays both endo- xylanase and exo-arabinofuranosidase activity


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.155 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Introducing Endo-Xylanase Activity Into an Exo-Acting Arabinofuranosidase that Targets Side Chains.

Mckee, L.S.Pena, M.J.Rogowski, A.Jackson, A.Lewis, R.J.York, W.S.Krogh, K.B.R.M.Vikso-Nielsen, A.Skjot, M.Gilbert, H.J.Marles-Wright, J.

(2012) Proc.Natl.Acad.Sci.USA 109: 6537

  • DOI: 10.1073/pnas.1117686109
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The degradation of the plant cell wall by glycoside hydrolases is central to environmentally sustainable industries. The major polysaccharides of the plant cell wall are cellulose and xylan, a highly decorated β-1,4-xylopyranose polymer. Glycoside hy ...

    The degradation of the plant cell wall by glycoside hydrolases is central to environmentally sustainable industries. The major polysaccharides of the plant cell wall are cellulose and xylan, a highly decorated β-1,4-xylopyranose polymer. Glycoside hydrolases displaying multiple catalytic functions may simplify the enzymes required to degrade plant cell walls, increasing the industrial potential of these composite structures. Here we test the hypothesis that glycoside hydrolase family 43 (GH43) provides a suitable scaffold for introducing additional catalytic functions into enzymes that target complex structures in the plant cell wall. We report the crystal structure of Humicola insolens AXHd3 (HiAXHd3), a GH43 arabinofuranosidase that hydrolyses O3-linked arabinose of doubly substituted xylans, a feature of the polysaccharide that is recalcitrant to degradation. HiAXHd3 displays an N-terminal five-bladed β-propeller domain and a C-terminal β-sandwich domain. The interface between the domains comprises a xylan binding cleft that houses the active site pocket. Substrate specificity is conferred by a shallow arabinose binding pocket adjacent to the deep active site pocket, and through the orientation of the xylan backbone. Modification of the rim of the active site introduces endo-xylanase activity, whereas the resultant enzyme variant, Y166A, retains arabinofuranosidase activity. These data show that the active site of HiAXHd3 is tuned to hydrolyse arabinofuranosyl or xylosyl linkages, and it is the topology of the distal regions of the substrate binding surface that confers specificity. This report demonstrates that GH43 provides a platform for generating bespoke multifunctional enzymes that target industrially significant complex substrates, exemplified by the plant cell wall.


    Organizational Affiliation

    Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HIAXHD3
A, B
542N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
BTB
Query on BTB

Download SDF File 
Download CCD File 
A, B
2-[BIS-(2-HYDROXY-ETHYL)-AMINO]-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
BIS-TRIS BUFFER
C8 H19 N O5
OWMVSZAMULFTJU-UHFFFAOYSA-N
 Ligand Interaction
PEG
Query on PEG

Download SDF File 
Download CCD File 
A, B
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.155 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 65.318α = 90.00
b = 78.260β = 103.13
c = 95.767γ = 90.00
Software Package:
Software NamePurpose
SHELXphasing
SCALAdata scaling
REFMACrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-04-18
    Type: Initial release
  • Version 1.1: 2012-05-02
    Type: Other