1OA3

Comparison of Family 12 Glycoside Hydrolases and Recruited Substitutions Important for Thermal Stability


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.192 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Comparison of Family 12 Glycoside Hydrolases and Recruited Substitutions Important for Thermal Stability

Sandgren, M.Gualfetti, P.J.Shaw, A.Gross, L.S.Saldajeno, M.Day, A.G.Jones, T.A.Mitchinson, C.

(2003) Protein Sci. 12: 848

  • DOI: 10.1110/ps.0237703
  • Primary Citation of Related Structures:  1OA2, 1OA4

  • PubMed Abstract: 
  • As part of a program to discover improved glycoside hydrolase family 12 (GH 12) endoglucanases, we have studied the biochemical diversity of several GH 12 homologs. The H. schweinitzii Cel12A enzyme differs from the T. reesei Cel12A enzyme by only 14 ...

    As part of a program to discover improved glycoside hydrolase family 12 (GH 12) endoglucanases, we have studied the biochemical diversity of several GH 12 homologs. The H. schweinitzii Cel12A enzyme differs from the T. reesei Cel12A enzyme by only 14 amino acids (93% sequence identity), but is much less thermally stable. The bacterial Cel12A enzyme from S. sp. 11AG8 shares only 28% sequence identity to the T. reesei enzyme, and is much more thermally stable. Each of the 14 sequence differences from H. schweinitzii Cel12A were introduced in T. reesei Cel12A to determine the effect of these amino acid substitutions on enzyme stability. Several of the T. reesei Cel12A variants were found to have increased stability, and the differences in apparent midpoint of thermal denaturation (T(m)) ranged from a 2.5 degrees C increase to a 4.0 degrees C decrease. The least stable recruitment from H. schweinitzii Cel12A was A35S. Consequently, the A35V substitution was recruited from the more stable S. sp. 11AG8 Cel12A and this T. reesei Cel12A variant was found to have a T(m) 7.7 degrees C higher than wild type. Thus, the buried residue at position 35 was shown to be of critical importance for thermal stability in this structural family. There was a ninefold range in the specific activities of the Cel12 homologs on o-NPC. The most and least stable T. reesei Cel12A variants, A35V and A35S, respectively, were fully active. Because of their thermal tolerance, S. sp. 11AG8 Cel12A and T. reesei Cel12A variant A35V showed a continual increase in activity over the temperature range of 25 degrees C to 60 degrees C, whereas the less stable enzymes T. reesei Cel12A wild type and the destabilized A35S variant, and H. schweinitzii Cel12A showed a decrease in activity at the highest temperatures. The crystal structures of the H. schweinitzii, S. sp. 11AG8, and T. reesei A35V Cel12A enzymes have been determined and compared with the wild-type T. reesei Cel12A enzyme. All of the structures have similar Calpha traces, but provide detailed insight into the nature of the stability differences. These results are an example of the power of homolog recruitment as a method for identifying residues important for stability.


    Organizational Affiliation

    Department of Cell and Molecular Biology, Uppsala University, Biomedical Center, SE-75124 Uppsala, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ENDO-BETA-1-4-GLUCANASE
A, B, C, D
218Trichoderma citrinovirideGene Names: cel12A
Find proteins for Q8NJY6 (Trichoderma citrinoviride)
Go to UniProtKB:  Q8NJY6
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download SDF File 
Download CCD File 
A, B, C, D
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PCA
Query on PCA
A, B, C, D
L-PEPTIDE LINKINGC5 H7 N O3GLU
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.192 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 62.490α = 90.00
b = 77.547β = 98.46
c = 83.410γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
AMoREphasing
REFMACrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-03-27
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance