PDBsum entry 3kcp

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protein metals Protein-protein interface(s) links
Structural protein PDB id
Protein chains
303 a.a. *
163 a.a. *
_CA ×2
Waters ×244
* Residue conservation analysis
PDB id:
Name: Structural protein
Title: Crystal structure of interacting clostridium thermocellum multimodular components
Structure: Cellulosomal-scaffolding protein a. Chain: a. Fragment: cohesin 9 and dockerin 1-2 domains: unp residues 1542-1853. Synonym: cellulosomal glycoprotein s1/sl, cellulose- integrating protein a, cohesin. Engineered: yes. Cellulosome anchoring protein, cohesin region. Chain: b.
Source: Clostridium thermocellum atcc 27405. Organism_taxid: 203119. Strain: atcc 27405 / dsm 1237. Gene: cipa, cthe_3077. Expressed in: escherichia coli. Expression_system_taxid: 562. Gene: cthe_1307, sdba. Expression_system_taxid: 562
1.94Å     R-factor:   0.206     R-free:   0.231
Authors: J.J.Adams,M.A.Currie,E.A.Bayer,Z.Jia,S.P.Smith
Key ref: J.J.Adams et al. (2010). Insights into higher-order organization of the cellulosome revealed by a dissect-and-build approach: crystal structure of interacting Clostridium thermocellum multimodular components. J Mol Biol, 396, 833-839. PubMed id: 20070943 DOI: 10.1016/j.jmb.2010.01.015
21-Oct-09     Release date:   09-Feb-10    
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Protein chain
Pfam   ArchSchema ?
Q06851  (CIPA_CLOTH) -  Cellulosomal-scaffolding protein A
1853 a.a.
303 a.a.
Protein chain
Pfam   ArchSchema ?
A3DF10  (A3DF10_CLOTH) -  Cellulosome anchoring protein cohesin region
631 a.a.
163 a.a.
Key:    PfamA domain  PfamB domain  Secondary structure  CATH domain

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     carbohydrate metabolic process   2 terms 
  Biochemical function     carbohydrate binding     2 terms  


DOI no: 10.1016/j.jmb.2010.01.015 J Mol Biol 396:833-839 (2010)
PubMed id: 20070943  
Insights into higher-order organization of the cellulosome revealed by a dissect-and-build approach: crystal structure of interacting Clostridium thermocellum multimodular components.
J.J.Adams, M.A.Currie, S.Ali, E.A.Bayer, Z.Jia, S.P.Smith.
Cellulosomes are large, multienzyme, plant cell wall-degrading protein complexes found affixed to the surface of a variety of anaerobic microbes. The core of the cellulosome is a noncatalytic scaffoldin protein, which contains several type-I cohesin modules that bind type-I dockerin-containing enzymatic subunits, a cellulose-binding module, an X module, and a type-II dockerin that interacts with type-II cohesin-containing cell surface proteins. The unique arrangement of the enzymatic subunits in the cellulosome complex, made possible by the scaffoldin subunit, promotes enhanced substrate degradation relative to the enzymes free in solution. Despite representative high-resolution structures of all of the individual modules of the cellulosome, this mechanism of enzymatic synergy remains poorly understood. Consequently, a model of the entire cellulosome and a detailed picture of intermodular contacts will provide more detailed insight into cellulosome activity. Toward this goal, we have solved the structure of a multimodular heterodimeric complex from Clostridium thermocellum composed of the type-II cohesin module of the cell surface protein SdbA bound to a trimodular C-terminal fragment of the scaffoldin subunit CipA to a resolution of 1.95 A. The linker that connects the ninth type-I cohesin module and the X module has elevated temperature factors, reflecting an inherent flexibility within this region. Interestingly, a novel dimer interface was observed between CipA and a second, symmetry-related CipA molecule within the crystal structure, mediated by contacts between a type-I cohesin and an X module of a symmetry mate, resulting in two intertwined scaffoldins. Sedimentation velocity experiments confirmed that dimerization also occurs in solution. These observations support the intriguing possibility that individual cellulosomes can associate with one another via inter-scaffoldin interactions, which may play a role in the mechanism of action of the complex.

Literature references that cite this PDB file's key reference

  PubMed id Reference
20591648 N.D.Clarke (2010).
Protein engineering for bioenergy and biomass-based chemicals.
  Curr Opin Struct Biol, 20, 527-532.  
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