3GZK

Structure of A. Acidocaldarius Cellulase CelA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.183 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal structures of A. acidocaldarius endoglucanase Cel9A in complex with cello-oligosaccharides: strong -1 and -2 subsites mimic cellobiohydrolase activity

Eckert, K.Vigouroux, A.Lo Leggio, L.Morera, S.

(2009) J.Mol.Biol. 394: 61-70

  • DOI: 10.1016/j.jmb.2009.08.060
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Alicyclobacillus acidocaldarius endoglucanase Cel9A (AaCel9A) is an inverting glycoside hydrolase with beta-1,4-glucanase activity on soluble polymeric substrates. Here, we report three X-ray structures of AaCel9A: a ligand-free structure at 1.8 A re ...

    Alicyclobacillus acidocaldarius endoglucanase Cel9A (AaCel9A) is an inverting glycoside hydrolase with beta-1,4-glucanase activity on soluble polymeric substrates. Here, we report three X-ray structures of AaCel9A: a ligand-free structure at 1.8 A resolution and two complexes at 2.66 and 2.1 A resolution, respectively, with cellobiose obtained by co-crystallization and with cellotetraose obtained by the soaking method. AaCel9A forms an (alpha/alpha)(6)-barrel like other glycoside hydrolase family 9 enzymes. When cellobiose is used as a ligand, three glucosyl binding subsites are occupied, including two on the glycone side, while with cellotetraose as a ligand, five subsites, including four on the glycone side, are occupied. A structural comparison showed no conformational rearrangement of AaCel9A upon ligand binding. The structural analysis demonstrates that of the four minus subsites identified, subsites -1 and -2 show the strongest interaction with bound glucose. In conjunction with the open active-site cleft of AaCel9A, this is able to reconcile the previously observed cleavage of short-chain oligosaccharides with cellobiose as main product with the endo mode of action on larger polysaccharides.


    Organizational Affiliation

    Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Cellulase
A
537Alicyclobacillus acidocaldariusMutation(s): 0 
Gene Names: celA
EC: 3.2.1.4
Find proteins for Q9AJS0 (Alicyclobacillus acidocaldarius)
Go to UniProtKB:  Q9AJS0
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

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Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

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Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
MPD
Query on MPD

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Download CCD File 
A
(4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.183 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 84.920α = 90.00
b = 129.300β = 90.00
c = 49.040γ = 90.00
Software Package:
Software NamePurpose
XDSdata scaling
REFMACrefinement
XDSdata reduction
PHASERphasing
ADSCdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-10-13
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance