PDBsum entry 1h0b

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Hydrolase PDB id
Protein chains
227 a.a. *
EPE ×2
Waters ×280
* Residue conservation analysis
PDB id:
Name: Hydrolase
Title: Endoglucanase cel12a from rhodothermus marinus
Structure: Cellulase. Chain: a, b. Fragment: catalytic domain, residues 38-260. Engineered: yes
Source: Rhodothermus marinus. Organism_taxid: 29549. Expressed in: escherichia coli. Expression_system_taxid: 511693. Expression_system_variant: lambda(de3)-lysogen.
1.8Å     R-factor:   0.173     R-free:   0.194
Authors: S.J.Crennell,G.O.Hreggvidsson,E.Nordberg-Karlsson
Key ref:
S.J.Crennell et al. (2002). The structure of Rhodothermus marinus Cel12A, a highly thermostable family 12 endoglucanase, at 1.8 A resolution. J Mol Biol, 320, 883-897. PubMed id: 12095262 DOI: 10.1016/S0022-2836(02)00446-1
17-Jun-02     Release date:   12-Jun-03    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
O33897  (O33897_RHOMR) -  Cellulase
260 a.a.
227 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 18 residue positions (black crosses)

 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     polysaccharide catabolic process   1 term 
  Biochemical function     hydrolase activity, hydrolyzing O-glycosyl compounds     2 terms  


DOI no: 10.1016/S0022-2836(02)00446-1 J Mol Biol 320:883-897 (2002)
PubMed id: 12095262  
The structure of Rhodothermus marinus Cel12A, a highly thermostable family 12 endoglucanase, at 1.8 A resolution.
S.J.Crennell, G.O.Hreggvidsson, E.Nordberg Karlsson.
Cellulose is one of the most abundant polysaccharides in nature and microorganisms have developed a comprehensive system for enzymatic breakdown of this ubiquitous carbon source, a subject of much interest in the biotechnology industry. Rhodothermus marinus produces a hyperthermostable cellulase, with a temperature optimum of more than 90 degrees C, the structure of which is presented here to 1.8 A resolution. The enzyme has been classified into glycoside hydrolase family 12; this is the first structure of a thermophilic member of this family to have been solved. The beta-jelly roll fold observed has identical topology to those of the two mesophilic members of the family whose structures have been elucidated previously. A Hepes buffer molecule bound in the active site may have triggered a conformational change to an active configuration as the two catalytic residues Glu124 and Glu207, together with dependent residues, are observed in a conformation similar to that seen in the structure of Streptomyces lividans CelB2 complexed with an inhibitor. The structural similarity between this cellulase and the mesophilic enzymes serves to highlight features that may be responsible for its thermostability, chiefly an increase in ion pair number and the considerable stabilisation of a mobile region seen in S. lividans CelB2. Additional aromatic residues in the active site region may also contribute to the difference in thermophilicity.
  Selected figure(s)  
Figure 1.
Figure 1. Schematic representation of the structure of R. marinus Cel12A, with sheet A shown in black and sheet B grey, drawn using MOLSCRIPT.[53] Individual strands are labelled according to their position within the sheets. The Hepes molecule bound in the active site is shown in a ball-and-stick representation.
Figure 4.
Figure 4. Schematic representations of the active sites of (a) Cel12A with Hepes bound and (b) CelB2 with 2-deoxy-2 fluorocellotrioside bound in the central -1 subsite, drawn using MOLSCRIPT[53] and Raster3D. [56] The amino acids that interact with cellulose are drawn with orange bonds, the inhibitor is shown in black (with the sugars in the -2 and -3 subsites of CelB2 drawn smaller for clarity), and hydrogen bonds as green dotted lines. The "cord" loop is coloured pale green.
  The above figures are reprinted by permission from Elsevier: J Mol Biol (2002, 320, 883-897) copyright 2002.  
  Figures were selected by the author.  
    Author's comment    
  See also 2bwa, 2bwc and 2bw8, for more recent structures of this protein with substrate bound.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
21082721 G.J.Forse, N.Ram, D.R.Banatao, D.Cascio, M.R.Sawaya, H.E.Klock, S.A.Lesley, and T.O.Yeates (2011).
Synthetic symmetrization in the crystallization and structure determination of CelA from Thermotoga maritima.
  Protein Sci, 20, 168-178.
PDB code: 3o7o
19205687 H.Nakazawa, K.Okada, T.Onodera, W.Ogasawara, H.Okada, and Y.Morikawa (2009).
Directed evolution of endoglucanase III (Cel12A) from Trichoderma reesei.
  Appl Microbiol Biotechnol, 83, 649-657.  
18606791 O.Stukalov, A.Korenevsky, T.J.Beveridge, and J.R.Dutcher (2008).
Use of atomic force microscopy and transmission electron microscopy for correlative studies of bacterial capsules.
  Appl Environ Microbiol, 74, 5457-5465.  
17359551 P.Turner, G.Mamo, and E.N.Karlsson (2007).
Potential and utilization of thermophiles and thermostable enzymes in biorefining.
  Microb Cell Fact, 6, 9.  
17376777 T.M.Gloster, F.M.Ibatullin, K.Macauley, J.M.Eklöf, S.Roberts, J.P.Turkenburg, M.E.Bjørnvad, P.L.Jørgensen, S.Danielsen, K.S.Johansen, T.V.Borchert, K.S.Wilson, H.Brumer, and G.J.Davies (2007).
Characterization and three-dimensional structures of two distinct bacterial xyloglucanases from families GH5 and GH12.
  J Biol Chem, 282, 19177-19189.
PDB codes: 2jem 2jen 2jep 2jeq
16075163 S.H.Bjornsdottir, T.Blondal, G.O.Hreggvidsson, G.Eggertsson, S.Petursdottir, S.Hjorleifsdottir, S.H.Thorbjarnardottir, and J.K.Kristjansson (2006).
Rhodothermus marinus: physiology and molecular biology.
  Extremophiles, 10, 1.  
12649442 M.Sandgren, P.J.Gualfetti, A.Shaw, L.S.Gross, M.Saldajeno, A.G.Day, T.A.Jones, and C.Mitchinson (2003).
Comparison of family 12 glycoside hydrolases and recruited substitutions important for thermal stability.
  Protein Sci, 12, 848-860.
PDB codes: 1oa2 1oa3 1oa4
14627738 M.Sandgren, P.J.Gualfetti, C.Paech, S.Paech, A.Shaw, L.S.Gross, M.Saldajeno, G.I.Berglund, T.A.Jones, and C.Mitchinson (2003).
The Humicola grisea Cel12A enzyme structure at 1.2 A resolution and the impact of its free cysteine residues on thermal stability.
  Protein Sci, 12, 2782-2793.
PDB codes: 1olq 1olr
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