PDBsum entry 2a39

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Endoglucanase PDB id
Protein chains
398 a.a. *
NAG ×4
Waters ×420
* Residue conservation analysis
PDB id:
Name: Endoglucanase
Title: Humicola insolens endocellulase egi native structure
Structure: Endoglucanase i. Chain: a, b. Synonym: cellulase, family 7 endoglucanase. Engineered: yes. Other_details: pyroglutamate post-translational modificatio residue 1 n-linked n-acetylglucosamine on residue asn 247
Source: Humicola insolens. Organism_taxid: 34413. Gene: potential. Expressed in: aspergillus oryzae. Expression_system_taxid: 5062
2.20Å     R-factor:   0.180     R-free:   0.230
Authors: G.J.Davies,G.Sulzenbacher,L.Mackenzie,S.G.Withers,C.Divne,T. H.F.Woldike,M.Schulein
Key ref: L.F.MacKenzie et al. (1998). Crystal structure of the family 7 endoglucanase I (Cel7B) from Humicola insolens at 2.2 A resolution and identification of the catalytic nucleophile by trapping of the covalent glycosyl-enzyme intermediate. Biochem J, 335, 409-416. PubMed id: 9761741
30-Jan-98     Release date:   16-Feb-99    
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Protein chains
Pfam   ArchSchema ?
P56680  (GUN1_HUMIN) -  Endoglucanase 1
402 a.a.
398 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Enzyme reactions 
   Enzyme class: E.C.  - Cellulase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: Endohydrolysis of 1,4-beta-D-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans.
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     extracellular region   1 term 
  Biological process     metabolic process   4 terms 
  Biochemical function     hydrolase activity     4 terms  


Biochem J 335:409-416 (1998)
PubMed id: 9761741  
Crystal structure of the family 7 endoglucanase I (Cel7B) from Humicola insolens at 2.2 A resolution and identification of the catalytic nucleophile by trapping of the covalent glycosyl-enzyme intermediate.
L.F.MacKenzie, G.Sulzenbacher, C.Divne, T.A.Jones, H.F.Wöldike, M.Schülein, S.G.Withers, G.J.Davies.
Cellulose is the major polysaccharide component of the plant cell wall and the most abundant naturally produced macromolecule on Earth. The enzymic degradation of cellulose, by cellulases, is therefore of great environmental and commercial significance. Cellulases are found in 12 of the glycoside hydrolase families classified according to their amino acid sequence similarities. Endoglucanase I (Cel7B), from the soft-rot fungus Humicola insolens, is a family 7 enzyme. The structure of the native form of Cel7B from H. insolens at 2.2 A resolution has been solved by molecular replacement using the known Trichoderma reesei cellobiohydrolase I [Divne, Ståhlberg, Reinikainen, Ruohonen, Pettersson, Knowles, Teeri and Jones (1994) Science 265, 524-528] structure as the search model. Cel7B catalyses hydrolysis of the beta-1,4 glycosidic linkages in cellulose with net retention of anomeric configuration. The catalytic nucleophile at the active site of Cel7B has been identified as Glu-197 by trapping of a 2-deoxy-2-fluorocellotriosyl enzyme intermediate and identification of the labelled peptide in peptic digests by tandem MS. Site-directed mutagenesis of both Glu-197 and the prospective catalytic acid, Glu-202, results in inactive enzyme, confirming the critical role of these groups for catalysis.

Literature references that cite this PDB file's key reference

  PubMed id Reference
18499583 T.Parkkinen, A.Koivula, J.Vehmaanperä, and J.Rouvinen (2008).
Crystal structures of Melanocarpus albomyces cellobiohydrolase Cel7B in complex with cello-oligomers show high flexibility in the substrate binding.
  Protein Sci, 17, 1383-1394.
PDB codes: 2rfw 2rfy 2rfz 2rg0
16138313 C.Mulakala, and P.J.Reilly (2005).
Force calculations in automated docking: enzyme-substrate interactions in Fusarium oxysporum Cel7B.
  Proteins, 61, 590-596.  
15819888 W.Ubhayasekera, I.G.Muñoz, A.Vasella, J.Ståhlberg, and S.L.Mowbray (2005).
Structures of Phanerochaete chrysosporium Cel7D in complex with product and inhibitors.
  FEBS J, 272, 1952-1964.
PDB codes: 1z3t 1z3v 1z3w
15062085 J.Allouch, W.Helbert, B.Henrissat, and M.Czjzek (2004).
Parallel substrate binding sites in a beta-agarase suggest a novel mode of action on double-helical agarose.
  Structure, 12, 623-632.
PDB code: 1urx
15130470 M.F.Amaya, A.G.Watts, I.Damager, A.Wehenkel, T.Nguyen, A.Buschiazzo, G.Paris, A.C.Frasch, S.G.Withers, and P.M.Alzari (2004).
Structural insights into the catalytic mechanism of Trypanosoma cruzi trans-sialidase.
  Structure, 12, 775-784.
PDB codes: 1s0i 1s0j 1s0k 2ah2
11866092 I.Kwon, K.Ekino, T.Oka, M.Goto, and K.Furukawa (2002).
Effects of amino acid alterations on the transglycosylation reaction of endoglucanase I from Trichoderma viride HK-75.
  Biosci Biotechnol Biochem, 66, 110-116.  
11754346 J.Karlsson, D.Momcilovic, B.Wittgren, M.Schülein, F.Tjerneld, and G.Brinkmalm (2002).
Enzymatic degradation of carboxymethyl cellulose hydrolyzed by the endoglucanases Cel5A, Cel7B, and Cel45A from Humicola insolens and Cel7B, Cel12A and Cel45Acore from Trichoderma reesei.
  Biopolymers, 63, 32-40.  
11135204 C.Boisset, C.Pétrequin, H.Chanzy, B.Henrissat, and M.Schülein (2001).
Optimized mixtures of recombinant Humicola insolens cellulases for the biodegradation of crystalline cellulose.
  Biotechnol Bioeng, 72, 339-345.  
11828460 S.Fort, A.Varrot, M.Schülein, S.Cottaz, H.Driguez, and G.J.Davies (2001).
Mixed-linkage cellooligosaccharides: a new class of glycoside hydrolase inhibitors.
  Chembiochem, 2, 319-325.
PDB code: 1e5j
11514661 W.A.Breyer, and B.W.Matthews (2001).
A structural basis for processivity.
  Protein Sci, 10, 1699-1711.  
10974122 R.Maheshwari, G.Bharadwaj, and M.K.Bhat (2000).
Thermophilic fungi: their physiology and enzymes.
  Microbiol Mol Biol Rev, 64, 461-488.  
10413461 A.Varrot, M.Schülein, and G.J.Davies (1999).
Structural changes of the active site tunnel of Humicola insolens cellobiohydrolase, Cel6A, upon oligosaccharide binding.
  Biochemistry, 38, 8884-8891.
PDB code: 2bvw
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