4JJJ

The structure of T. fusca GH48 D224N mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.164 
  • R-Value Work: 0.121 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Cel48A from Thermobifida fusca: structure and site directed mutagenesis of key residues.

Kostylev, M.Alahuhta, M.Chen, M.Brunecky, R.Himmel, M.E.Lunin, V.V.Brady, J.Wilson, D.B.

(2014) Biotechnol.Bioeng. 111: 664-673

  • DOI: 10.1002/bit.25139

  • PubMed Abstract: 
  • Lignocellulosic biomass is a potential source of sustainable transportation fuels, but efficient enzymatic saccharification of cellulose is a key challenge in its utilization. Cellulases from the glycoside hydrolase (GH) family 48 constitute an impor ...

    Lignocellulosic biomass is a potential source of sustainable transportation fuels, but efficient enzymatic saccharification of cellulose is a key challenge in its utilization. Cellulases from the glycoside hydrolase (GH) family 48 constitute an important component of bacterial biomass degrading systems and structures of three enzymes from this family have been previously published. We report a new crystal structure of TfCel48A, a reducing end directed exocellulase from Thermobifida fusca, which shows that this enzyme shares important structural features with the other members of the GH48 family. The active site tunnel entrance of the known GH48 exocellulases is enriched in aromatic residues, which are known to interact well with anhydroglucose units of cellulose. We carried out site-directed mutagenesis studies of these aromatic residues (Y97, F195, Y213, and W313) along with two non-aromatic residues (N212 and S311) also located around the tunnel entrance and a W315 residue inside the active site tunnel. Only the aromatic residues located around the tunnel entrance appear to be important for the ability of TfCel48A to access individual cellulose chains on bacterial cellulose (BC), a crystalline substrate. Both Trp residues were found to be important for the processivity of TfCel48A on BC and phosphoric acid swollen cellulose (PASC), but only W313 appears to play a role in the ability of the enzyme to access individual cellulose chains in BC. When acting on BC, reduced processivity was found to correlate with reduced enzyme activity. The reverse, however, is true when PASC is the substrate. Presumably, higher density of available cellulose chain ends and the amorphous nature of PASC explain the increased initial activity of mutants with lower processivity.


    Organizational Affiliation

    Department of Molecular Biology and Genetics, Cornell University, 458 Biotechnology Building, Ithaca, New York, 14853. mk377@cornell.edu.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Cellulose 1,4-beta-cellobiosidase
A
642Thermobifida fusca (strain YX)Mutation(s): 1 
EC: 3.2.1.91
Find proteins for Q47NH7 (Thermobifida fusca (strain YX))
Go to UniProtKB:  Q47NH7
Small Molecules
Ligands 9 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CBI
Query on CBI

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A
CELLOBIOSE
C12 H22 O11
GUBGYTABKSRVRQ-QRZGKKJRSA-N
 Ligand Interaction
ZN
Query on ZN

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A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
CBK
Query on CBK

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A
4-O-beta-D-glucopyranosyl-alpha-D-glucopyranose
C12 H22 O11
GUBGYTABKSRVRQ-MFRLZQSSSA-N
 Ligand Interaction
NA
Query on NA

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A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
CE6
Query on CE6

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A
CELLOHEXAOSE
C36 H62 O31
OCIBBXPLUVYKCH-FYTDUCIRSA-N
 Ligand Interaction
ACT
Query on ACT

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A
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CA
Query on CA

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A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
EDO
Query on EDO

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A
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
FE
Query on FE

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A
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.164 
  • R-Value Work: 0.121 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 56.458α = 90.00
b = 88.494β = 113.72
c = 66.753γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
PROTEUM PLUSdata reduction
MOLREPphasing
PROTEUM PLUSdata collection
PROTEUM PLUSdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-07-30
    Type: Initial release