Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

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

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 72.44 kDa 
• Atom Count: 5402 
• Modelled Residue Count: 621 
• Deposited Residue Count: 634 
• Unique protein chains: 1

4EL8

The unliganded structure of C.bescii CelA GH48 module

• PDB DOI: 10.2210/pdb4EL8/pdb

• Classification: HYDROLASE
• Organism(s): Caldicellulosiruptor bescii DSM 6725
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2012-04-10 Released: 2013-03-20 
• Deposition Author(s): Alahuhta, P.M., Lunin, V.V.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.45 Å
• R-Value Free: 0.258 
• R-Value Work: 0.195 
• R-Value Observed: 0.199 

Literature

Revealing nature's cellulase diversity: the digestion mechanism of Caldicellulosiruptor bescii CelA.

Brunecky, R., Alahuhta, M., Xu, Q., Donohoe, B.S., Crowley, M.F., Kataeva, I.A., Yang, S.J., Resch, M.G., Adams, M.W., Lunin, V.V., Himmel, M.E., Bomble, Y.J.

(2013) Science 342: 1513-1516

• PubMed: 24357319 
• DOI: 10.1126/science.1244273
• Primary Citation of Related Structures:  
  4DOD, 4DOE, 4EL8


• PubMed Abstract: 
  

Most fungi and bacteria degrade plant cell walls by secreting free, complementary enzymes that hydrolyze cellulose; however, some bacteria use large enzymatic assemblies called cellulosomes, which recruit complementary enzymes to protein scaffolds. The thermophilic bacterium Caldicellulosiruptor bescii uses an intermediate strategy, secreting many free cellulases that contain multiple catalytic domains. One of these, CelA, comprises a glycoside hydrolase family 9 and a family 48 catalytic domain, as well as three type III cellulose-binding modules. In the saccharification of a common cellulose standard, Avicel, CelA outperforms mixtures of commercially relevant exo- and endoglucanases. From transmission electron microscopy studies of cellulose after incubation with CelA, we report morphological features that suggest that CelA not only exploits the common surface ablation mechanism driven by general cellulase processivity, but also excavates extensive cavities into the surface of the substrate. These results suggest that nature's repertoire of cellulose digestion paradigms remain only partially discovered and understood.

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Organizational Affiliation: 

Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Glycoside hydrolase family 48	A	634	Caldicellulosiruptor bescii DSM 6725	Mutation(s): 0  Gene Names: Athe_1867 EC: 3.2.1.4
UniProt
Find proteins for B9MKU7 (Caldicellulosiruptor bescii (strain ATCC BAA-1888 / DSM 6725 / Z-1320)) Explore B9MKU7  Go to UniProtKB:  B9MKU7

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SO4	C [auth A]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L
EDO	D [auth A]	1,2-ETHANEDIOL C2 H6 O2 LYCAIKOWRPUZTN-UHFFFAOYSA-N
CA	B [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.45 Å
• R-Value Free: 0.258 
• R-Value Work: 0.195 
• R-Value Observed: 0.199 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 116.3	α = 90
b = 57.666	β = 102.3
c = 106.06	γ = 90

Software Package:

Software Name	Purpose
PROTEUM PLUS	data collection
MrBUMP	phasing
REFMAC	refinement
PROTEUM PLUS	data reduction
PROTEUM PLUS	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2012-04-10 
• Released Date: 2013-03-20 
Deposition Author(s): Alahuhta, P.M., Lunin, V.V.

Revision History  

• Version 1.0: 2013-03-20
  Type: Initial release
  
• Version 1.1: 2019-06-05
  Changes: Data collection, Database references