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PDBsum entry 2eex

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protein ligands metals links
Hydrolase PDB id
2eex
Jmol
Contents
Protein chain
509 a.a. *
Ligands
CE5
GOL ×2
Metals
_ZN
_CA
_CL
Waters ×459
* Residue conservation analysis
PDB id:
2eex
Name: Hydrolase
Title: Crystal structure of cel44a, gh family 44 endoglucanase from clostridium thermocellum
Structure: Endoglucanase. Chain: a. Fragment: residues 1-519. Synonym: glycoside hydrolase. Engineered: yes. Mutation: yes
Source: Clostridium thermocellum. Organism_taxid: 1515. Strain: f1. Gene: cel44a. Expressed in: escherichia coli. Expression_system_taxid: 562.
Resolution:
2.00Å     R-factor:   0.165     R-free:   0.201
Authors: Y.Kitago,S.Karita,N.Watanabe,K.Sakka,I.Tanaka
Key ref:
Y.Kitago et al. (2007). Crystal structure of Cel44A, a glycoside hydrolase family 44 endoglucanase from Clostridium thermocellum. J Biol Chem, 282, 35703-35711. PubMed id: 17905739 DOI: 10.1074/jbc.M706835200
Date:
19-Feb-07     Release date:   18-Sep-07    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chain
Pfam   ArchSchema ?
A3DD30  (A3DD30_CLOTH) -  Glycoside hydrolase family 9
Seq:
Struc:
 
Seq:
Struc:
 
Seq:
Struc:
 
Seq:
Struc:
1601 a.a.
509 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     carbohydrate metabolic process   1 term 

 

 
DOI no: 10.1074/jbc.M706835200 J Biol Chem 282:35703-35711 (2007)
PubMed id: 17905739  
 
 
Crystal structure of Cel44A, a glycoside hydrolase family 44 endoglucanase from Clostridium thermocellum.
Y.Kitago, S.Karita, N.Watanabe, M.Kamiya, T.Aizawa, K.Sakka, I.Tanaka.
 
  ABSTRACT  
 
The crystal structure of Cel44A, which is one of the enzymatic components of the cellulosome of Clostridium thermocellum, was solved at a resolution of 0.96 A. This enzyme belongs to glycoside hydrolase family (GH family) 44. The structure reveals that Cel44A consists of a TIM-like barrel domain and a beta-sandwich domain. The wild-type and the E186Q mutant structures complexed with substrates suggest that two glutamic acid residues, Glu(186) and Glu(359), are the active residues of the enzyme. Biochemical experiments were performed to confirm this idea. The structural features indicate that GH family 44 belongs to clan GH-A and that the reaction catalyzed by Cel44A is retaining type hydrolysis. The stereochemical course of hydrolysis was confirmed by a (1)H NMR experiment using the reduced cellooligosaccharide as a substrate.
 
  Selected figure(s)  
 
Figure 2.
a, the reaction product recognition of the minus subsite observed with F[o] – F[c] electron density map contoured 2.0σ in the wild-type crystal structure complexed with cellohexaose. b, the substrate-recognizing residues and four hydrogen bonds between the reaction product and the wild-type Cel44A molecule in the crystal structure. c, close up stereoview of the reducing end pyranose ring. The F[o] – F[c] electron density map is shown as a gray surface contoured 2.0σ. The map is shown in the region of 3.0 Å distance around the substrate in a and c.
Figure 5.
The F[o] – F[c] electron density map contoured at 2.2σ around subsite –1 in the E186Q mutant complexed with a high concentration of cellohexaose. The map is shown in the region of 3.0 Å distance around the substrate. Shown is the model of the E186Q mutant structure complexed with a high concentration of cellohexaose.
 
  The above figures are reprinted by permission from the ASBMB: J Biol Chem (2007, 282, 35703-35711) copyright 2007.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
19915043 C.D.Warner, J.A.Hoy, T.C.Shilling, M.J.Linnen, N.D.Ginder, C.F.Ford, R.B.Honzatko, and P.J.Reilly (2010).
Tertiary structure and characterization of a glycoside hydrolase family 44 endoglucanase from Clostridium acetobutylicum.
  Appl Environ Microbiol, 76, 338-346.
PDB code: 3ik2
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