4U3A

Crystal structure of CtCel5E

• PDB DOI: https://doi.org/10.2210/pdb4U3A/pdb

• Classification: HYDROLASE
• Organism(s): Acetivibrio thermocellus ATCC 27405
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2014-07-19 Released: 2015-01-14 
• Deposition Author(s): Yuan, S.F., Liang, P.H., Ho, M.C.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.42 Å
• R-Value Free: 0.248 
• R-Value Work: 0.201 
• R-Value Observed: 0.204 

Literature

Biochemical Characterization and Structural Analysis of a Bifunctional Cellulase/Xylanase from Clostridium thermocellum

Yuan, S.F., Wu, T.H., Lee, H.L., Hsieh, H.Y., Lin, W.L., Yang, B., Chang, C.K., Li, Q., Gao, J., Huang, C.H., Ho, M.C., Guo, R.T., Liang, P.H.

(2015) J Biol Chem 290: 5739-5748

• PubMed: 25575592 
• DOI: https://doi.org/10.1074/jbc.M114.604454
• Primary Citation of Related Structures:  
  4U3A


• PubMed Abstract: 
  

  We expressed an active form of CtCel5E (a bifunctional cellulase/xylanase from Clostridium thermocellum), performed biochemical characterization, and determined its apo- and ligand-bound crystal structures. From the structures, Asn-93, His-168, His-169, Asn-208, Trp-347, and Asn-349 were shown to provide hydrogen-bonding/hydrophobic interactions with both ligands. Compared with the structures of TmCel5A, a bifunctional cellulase/mannanase homolog from Thermotoga maritima, a flexible loop region in CtCel5E is the key for discriminating substrates. Moreover, site-directed mutagenesis data confirmed that His-168 is essential for xylanase activity, and His-169 is more important for xylanase activity, whereas Asn-93, Asn-208, Tyr-270, Trp-347, and Asn-349 are critical for both activities. In contrast, F267A improves enzyme activities.

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Organizational Affiliation: 

the Institute of Biochemical Sciences, and.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Biological Assembly 2  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 2 assigned by authors.

Macromolecule Content

• Total Structure Weight: 92.5 kDa 
• Atom Count: 4,930 
• Modelled Residue Count: 586 
• Deposited Residue Count: 806 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Endoglucanase H	A, B	403	Acetivibrio thermocellus ATCC 27405	Mutation(s): 0  Gene Names: celH, Cthe_1472 EC: 3.2.1.4
UniProt
Find proteins for P16218 (Acetivibrio thermocellus (strain ATCC 27405 / DSM 1237 / JCM 9322 / NBRC 103400 / NCIMB 10682 / NRRL B-4536 / VPI 7372)) Explore P16218  Go to UniProtKB:  P16218

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.42 Å
• R-Value Free: 0.248 
• R-Value Work: 0.201 
• R-Value Observed: 0.204 
• Space Group: P 4₃ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 74.93	α = 90
b = 74.93	β = 90
c = 254.195	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement

Structure Validation

Entry History 

Deposition Data

• Released Date: 2015-01-14 
Deposition Author(s): Yuan, S.F., Liang, P.H., Ho, M.C.

Revision History  

• Version 1.0: 2015-01-14
  Type: Initial release
  
• Version 1.1: 2015-02-18
  Changes: Database references
• Version 1.2: 2015-03-11
  Changes: Database references
• Version 1.3: 2017-08-30
  Changes: Data collection, Database references, Derived calculations, Source and taxonomy
• Version 1.4: 2017-10-04
  Changes: Data collection
• Version 1.5: 2024-03-20
  Changes: Data collection, Database references