1g1k
From Proteopedia
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COHESIN MODULE FROM THE CELLULOSOME OF CLOSTRIDIUM CELLULOLYTICUM
Overview
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.
About this Structure
1G1K is a Single protein structure of sequence from Clostridium cellulolyticum. Full crystallographic information is available from OCA.
Reference
Crystal structure of a cohesin module from Clostridium cellulolyticum: implications for dockerin recognition., Spinelli S, Fierobe HP, Belaich A, Belaich JP, Henrissat B, Cambillau C, J Mol Biol. 2000 Nov 24;304(2):189-200. PMID:11080455
Page seeded by OCA on Sun Nov 25 00:40:03 2007
