1G1K

COHESIN MODULE FROM THE CELLULOSOME OF CLOSTRIDIUM CELLULOLYTICUM

Summary for 1G1K

• Entry DOI: 10.2210/pdb1g1k/pdb
• Related: 1ANU 1AOH
• Descriptor: SCAFFOLDING PROTEIN (2 entities in total)
• Functional Keywords: beta -barrel, structural protein
• Biological source: Clostridium cellulolyticum
• Total number of polymer chains: 2
• Total formula weight: 29297.08

Authors

Spinelli, S.,Fierobe, H.-P.,Belaich, A.,Belaich, J.-P.,Henrissat, B.,Cambillau, C. (deposition date: 2000-10-12, release date: 2000-11-22, Last modification date: 2024-02-07)

Primary citation

Spinelli, S.,Fierobe, H.P.,Belaich, A.,Belaich, J.P.,Henrissat, B.,Cambillau, C.
Crystal structure of a cohesin module from Clostridium cellulolyticum: implications for dockerin recognition.
J.Mol.Biol., 304:189-200, 2000

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.

PubMed: 11080455
DOI: 10.1006/jmbi.2000.4191

Experimental method

X-RAY DIFFRACTION (2 Å)