PDBsum entry 1ia6

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Hydrolase PDB id
Protein chain
423 a.a. *
Waters ×262
* Residue conservation analysis
PDB id:
Name: Hydrolase
Title: Crystal structure of the cellulase cel9m of c. Cellulolyticum
Structure: Cellulase cel9m. Chain: a. Fragment: catalytic module. Engineered: yes
Source: Clostridium cellulolyticum. Organism_taxid: 1521. Expressed in: escherichia coli. Expression_system_taxid: 562.
1.80Å     R-factor:   0.158     R-free:   0.189
Authors: G.Parsiegla,A.Belaich,J.P.Belaich,R.Haser
Key ref:
G.Parsiegla et al. (2002). Crystal structure of the cellulase Cel9M enlightens structure/function relationships of the variable catalytic modules in glycoside hydrolases. Biochemistry, 41, 11134-11142. PubMed id: 12220178 DOI: 10.1021/bi025816m
22-Mar-01     Release date:   30-Oct-02    
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Protein chain
Pfam   ArchSchema ?
Q9EYQ2  (Q9EYQ2_9CLOT) -  Cellulase Cel9-M
526 a.a.
423 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!
  Biological process     carbohydrate metabolic process   1 term 
  Biochemical function     catalytic activity     2 terms  


DOI no: 10.1021/bi025816m Biochemistry 41:11134-11142 (2002)
PubMed id: 12220178  
Crystal structure of the cellulase Cel9M enlightens structure/function relationships of the variable catalytic modules in glycoside hydrolases.
G.Parsiegla, A.Belaïch, J.P.Belaïch, R.Haser.
Cellulases cleave the beta-1.4 glycosidic bond of cellulose. They have been characterized as endo or exo and processive or nonprocessive cellulases according to their action mode on the substrate. Different types of these cellulases may coexist in the same glycoside hydrolase family, which have been classified according to their sequence homology and catalytic mechanism. The bacterium C. celluloyticum produces a set of different cellulases who belong mostly to glycoside hydrolase families 5 and 9. As an adaptation of the organism to different macroscopic substrates organizations and to maximize its cooperative digestion, it is expected that cellulases of these families are active on the various macroscopic organizations of cellulose chains. The nonprocessive cellulase Cel9M is the shortest variant of family 9 cellulases (subgroup 9(C)) which contains only the catalytic module to interact with the substrate. The crystal structures of free native Cel9M and its complex with cellobiose have been solved to 1.8 and 2.0 A resolution, respectively. Other structurally known family 9 cellulases are the nonprocessive endo-cellulase Cel9D from C. thermocellum and the processive endo-cellulase Cel9A from T. fusca, from subgroups 9(B1) and 9(A), respectively, whose catalytic modules are fused to a second domain. These enzymes differ in their activity on substrates with specific macroscopic appearances. The comparison of the catalytic module of Cel9M with the two other known GH family 9 structures may give clues to explain its substrate profile and action mode.

Literature references that cite this PDB file's key reference

  PubMed id Reference
21098515 Y.Honda, N.Shimaya, K.Ishisaki, M.Ebihara, and H.Taniguchi (2011).
Elucidation of exo-{beta}-D-glucosaminidase activity of a family 9 glycoside hydrolase (PBPRA0520) from Photobacterium profundum SS9.
  Glycobiology, 21, 503-511.  
19622857 J.H.Pereira, R.Sapra, J.V.Volponi, C.L.Kozina, B.Simmons, and P.D.Adams (2009).
Structure of endoglucanase Cel9A from the thermoacidophilic Alicyclobacillus acidocaldarius.
  Acta Crystallogr D Biol Crystallogr, 65, 744-750.
PDB code: 3ez8
18663584 L.C.Tsai, Y.N.Chen, and L.F.Shyur (2008).
Structural modeling of glucanase-substrate complexes suggests a conserved tyrosine is involved in carbohydrate recognition in plant 1,3-1,4-beta-D-glucanases.
  J Comput Aided Mol Des, 22, 915-923.  
17022659 M.Desvaux (2006).
Unravelling carbon metabolism in anaerobic cellulolytic bacteria.
  Biotechnol Prog, 22, 1229-1238.  
16102601 M.Desvaux (2005).
Clostridium cellulolyticum: model organism of mesophilic cellulolytic clostridia.
  FEMS Microbiol Rev, 29, 741-764.  
15604820 L.Hildén, and G.Johansson (2004).
Recent developments on cellulases and carbohydrate-binding modules with cellulose affinity.
  Biotechnol Lett, 26, 1683-1693.  
15148314 T.Itoh, S.Akao, W.Hashimoto, B.Mikami, and K.Murata (2004).
Crystal structure of unsaturated glucuronyl hydrolase, responsible for the degradation of glycosaminoglycan, from Bacillus sp. GL1 at 1.8 A resolution.
  J Biol Chem, 279, 31804-31812.
PDB code: 1vd5
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