2CCL

THE S45A, T46A MUTANT OF THE TYPE I COHESIN-DOCKERIN COMPLEX FROM THE CELLULOSOME OF CLOSTRIDIUM THERMOCELLUM

Summary for 2CCL

• Entry DOI: 10.2210/pdb2ccl/pdb
• Related: 1ANU 1AOH 1DYO 1GKK 1GKL 1H6X 1H6Y 1NBC 1OHZ 1WB4 1WB5 1WB6
• Descriptor: CELLULOSOMAL SCAFFOLDING PROTEIN A, ENDO-1,4-BETA-XYLANASE Y, PHOSPHATE ION, ... (5 entities in total)
• Functional Keywords: cell adhesion, cohesin-dockerin complex, cellulosome, cohesin, dockerin, clostridium thermocellum, scaffolding, cellulose degradation, hydrolase, glycosidase
• Biological source: CLOSTRIDIUM THERMOCELLUM; More
• Total number of polymer chains: 4
• Total formula weight: 47852.02

Authors

Carvalho, A.L.,Dias, F.M.V.,Prates, J.A.M.,Ferreira, L.M.A.,Gilbert, H.J.,Davies, G.J.,Romao, M.J.,Fontes, C.M.G.A. (deposition date: 2006-01-16, release date: 2007-02-13, Last modification date: 2023-12-13)

Primary citation

Carvalho, A.L.,Dias, F.M.V.,Nagy, T.,Prates, J.A.M.,Proctor, M.R.,Smith, N.,Bayer, E.A.,Davies, G.J.,Ferreira, L.M.A.,Romao, M.J.,Fontes, C.M.G.A.,Gilbert, H.J.
Evidence for a Dual Binding Mode of Dockerin Modules to Cohesins.
Proc.Natl.Acad.Sci.USA, 104:3089-, 2007

PubMed Abstract: The assembly of proteins that display complementary activities into macromolecular complexes is critical to cellular function. One such enzyme complex, of environmental significance, is the plant cell wall degrading apparatus of anaerobic bacteria, termed the cellulosome. The complex assembles through the interaction of enzyme-derived "type I dockerin" modules with the multiple "cohesin" modules of the scaffolding protein. Clostridium thermocellum type I dockerin modules contain a duplicated 22-residue sequence that comprises helix-1 and helix-3, respectively. The crystal structure of a C. thermocellum type I cohesin-dockerin complex showed that cohesin recognition was predominantly through helix-3 of the dockerin. The sequence duplication is reflected in near-perfect 2-fold structural symmetry, suggesting that both repeats could interact with cohesins by a common mechanism in wild-type (WT) proteins. Here, a helix-3 disrupted mutant dockerin is used to visualize the reverse binding in which the dockerin mutant is indeed rotated 180 degrees relative to the WT dockerin such that helix-1 now dominates recognition of its protein partner. The dual binding mode is predicted to impart significant plasticity into the orientation of the catalytic subunits within this supramolecular assembly, which reflects the challenges presented by the degradation of a heterogeneous, recalcitrant, insoluble substrate by a tethered macromolecular complex.

PubMed: 17360613
DOI: 10.1073/PNAS.0611173104

Experimental method

X-RAY DIFFRACTION (2.03 Å)