PDBsum entry 1wzz

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Hydrolase PDB id
Protein chain
319 a.a. *
Waters ×312
* Residue conservation analysis
PDB id:
Name: Hydrolase
Title: Structure of endo-beta-1,4-glucanase cmcax from acetobacter xylinum
Structure: Probable endoglucanase. Chain: a. Synonym: endo-beta-1,4-glucanase, endo-1,4-beta- glucanase, cellulase. Engineered: yes
Source: Gluconacetobacter xylinus. Organism_taxid: 28448. Gene: cmcax. Expressed in: escherichia coli. Expression_system_taxid: 562.
1.65Å     R-factor:   0.176     R-free:   0.195
Authors: Y.Yasutake,S.Kawano,K.Tajima,M.Yao,Y.Satoh,M.Munekata, I.Tanaka,Structural Genomics Consortium (Sgc)
Key ref:
Y.Yasutake et al. (2006). Structural characterization of the Acetobacter xylinum endo-beta-1,4-glucanase CMCax required for cellulose biosynthesis. Proteins, 64, 1069-1077. PubMed id: 16804941 DOI: 10.1002/prot.21052
10-Mar-05     Release date:   14-Mar-06    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
P37696  (GUNA_GLUHA) -  Probable endoglucanase
342 a.a.
319 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 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     catalytic activity     5 terms  


DOI no: 10.1002/prot.21052 Proteins 64:1069-1077 (2006)
PubMed id: 16804941  
Structural characterization of the Acetobacter xylinum endo-beta-1,4-glucanase CMCax required for cellulose biosynthesis.
Y.Yasutake, S.Kawano, K.Tajima, M.Yao, Y.Satoh, M.Munekata, I.Tanaka.
Previous studies have demonstrated that endoglucanase is required for cellulose biosynthesis both in bacteria and plants. However, it has yet to be elucidated how the endoglucanases function in the mechanism of cellulose biosynthesis. Here we describe the crystal structure of the cellulose biosynthesis-related endo-beta-1,47-glucanase (CMCax; EC from the cellulose-producing Gramnegative bacterium, Acetobacter xylinum (= Gluconacetobacter xylinus), determined at 1.65-A resolution. CMCax falls into the glycoside hydrolase family 8 (GH-8), and the structure showed that the overall fold of the CMCax is similar to those of other glycoside hydrolases belonging to GH-8. Structure comparison with Clostridium thermocellum CelA, the best characterized GH-8 endoglucanase, revealed that sugar recognition subsite +3 is completely missing in CMCax. The absence of the subsite +3 leads to significant broadness of the cleft at the cellooligosaccharide reducing-end side. CMCax is known to be a secreted enzyme and is present in the culture medium. However, electron microscopic analysis using immunostaining clearly demonstrated that a portion of CMCax is localized to the cell surface, suggesting a link with other known membrane-anchored endoglucanases that are required for cellulose biosynthesis.
  Selected figure(s)  
Figure 1.
Figure 1. Stereo view representation of the CMCax structure. A: Top view of the CMCax structure. Secondary structure elements are labeled. B: Side view of the structure in (A). The active site cleft and the N- and C-termini are indicated. All drawings were prepared using PyMol (DeLano Scientific LLC,
Figure 3.
Figure 3. Stereo view of cellooligosaccharide recognition cleft. A: CtCelA (PDB code, 1kwf).[39] Thanks to the ultra high-resolution data, the model includes multiple conformations. B: CMCax. The model in (A) was superimposed on the CMCax structure with the program LSQKAB.[44] The side chains of catalytic residues and of aromatic residues creating sugar recognition subsites are depicted as a ball-and-stick model.
  The above figures are reprinted by permission from John Wiley & Sons, Inc.: Proteins (2006, 64, 1069-1077) copyright 2006.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
20571949 X.Huang, Z.Shao, Y.Hong, L.Lin, C.Li, F.Huang, H.Wang, and Z.Liu (2010).
Cel8H, a novel endoglucanase from the halophilic bacterium Halomonas sp. S66-4: molecular cloning, heterogonous expression, and biochemical characterization.
  J Microbiol, 48, 318-324.  
18820969 D.O.Recouvreux, C.A.Carminatti, A.K.Pitlovanciv, C.R.Rambo, L.M.Porto, and R.V.Antônio (2008).
Cellulose biosynthesis by the beta-proteobacterium, Chromobacterium violaceum.
  Curr Microbiol, 57, 469-476.  
18691537 S.Kawano, K.Tajima, H.Kono, Y.Numata, H.Yamashita, Y.Satoh, and M.Munekata (2008).
Regulation of endoglucanase gene (cmcax) expression in Acetobacter xylinum.
  J Biosci Bioeng, 106, 88-94.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time.