Download MendeleyCrystal structure of a cohesin module from Clostridium cellulolyticum: implications for dockerin recognition.
Spinelli, S., Fierobe, H.P., Belaich, A., Belaich, J.P., Henrissat, B., Cambillau, C.(2000) J Mol Biol 304: 189-200
- PubMed: 11080455
- DOI: https://doi.org/10.1006/jmbi.2000.4191
- Primary Citation of Related Structures:
1G1K - PubMed Abstract:
In the assembly of the Clostridium cellulolyticum cellulosome, the multiple cohesin modules of the scaffolding protein CipC serve as receptors for cellulolytic enzymes which bear a dockerin module. The X-ray structure of a type I C. cellulolyticum cohesin module (Cc-cohesin) has been solved using molecular replacement, and refined at 2.0 A resolution. Despite a rather low sequence identity of 32 %, this module has a fold close to those of the two Clostridium thermocellum cohesin (Ct-cohesin) modules whose 3D structures have been determined previously. Cc-cohesin forms a dimer in the crystal, as do the two Ct-cohesins. We show here that the dimer exists in solution and that addition of dockerin-containing proteins dissociates the dimer. This suggests that the dimerization interface and the cohesin/dockerin interface may overlap. The nature of the overall surface and of the dimer interface of Cc-cohesin differ notably from those of the Ct-cohesin modules, being much less polar, and this may explain the species specificity observed in the cohesin/dockerin interaction of C. cellulolyticum and C. thermocellum. We have produced a topology model of a C. cellulolyticum dockerin and of a Cc-cohesin/dockerin complex using homology modeling and available biochemical data. Our model suggests that a special residue pair, already identified in dockerin sequences, is located at the center of the cohesin surface putatively interacting with the dockerin.
Organizational Affiliation:
Architecture et Fonction des Macromolécules Biologiques, UMR 6098, CNRS-Universités de Marseille I et II, 31 Chemin Joseph-Aiguier, Marseille, Cedex 20, 13402, France.
