2BM3

Structure of the Type II cohesin from Clostridium thermocellum SdbA

Summary for 2BM3

• Entry DOI: 10.2210/pdb2bm3/pdb
• Descriptor: SCAFFOLDING DOCKERIN BINDING PROTEIN A, ISOPROPYL ALCOHOL (3 entities in total)
• Functional Keywords: cohesin, type 2, cellulosome, dockerin, nuclear protein
• Biological source: CLOSTRIDIUM THERMOCELLUM
• Total number of polymer chains: 1
• Total formula weight: 18302.83

Authors

Carvalho, A.L.,Gloster, T.M.,Pires, V.M.R.,Proctor, M.R.,Prates, J.A.M.,Ferreira, L.M.A.,Turkenburg, J.P.,Romao, M.J.,Davies, G.J.,Gilbert, H.J.,Fontes, C.M.G.A. (deposition date: 2005-03-09, release date: 2005-03-10, Last modification date: 2024-05-08)

Primary citation

Carvalho, A.L.,Pires, V.M.R.,Gloster, T.M.,Turkenburg, J.P.,Prates, J.A.M.,Ferreira, L.M.A.,Romao, M.J.,Davies, G.J.,Fontes, C.M.G.A.,Gilbert, H.J.
Insights Into the Structural Determinants of Cohesin-Dockerin Specificity Revealed by the Crystal Structure of the Type II Cohesin from Clostridium Thermocellum Sdba.
J.Mol.Biol., 349:909-, 2005

PubMed Abstract: The plant cell wall degrading enzymes expressed by anaerobic microorganisms form large multienzyme complexes (cellulosomes). Cellulosomes assemble by the Type I dockerins on the catalytic subunits binding to the reiterated Type I cohesins in the molecular scaffold, while Type II dockerin-cohesin interactions anchor the complex onto the bacterial cell surface. Type I and Type II cohesin, dockerin pairs show no cross-specificity. Here we report the crystal structure of the Type II cohesin (CohII) from the Clostridium thermocellum cell surface anchoring protein SdbA. The protein domain contains nine beta-strands and a small alpha-helix. The beta-strands assemble into two elongated beta-sheets that display a typical jelly roll fold. The structure of CohII is very similar to Type I cohesins, and the dockerin binding site, which is centred at beta-strands 3, 5 and 6, is likely to be conserved in the two proteins. Subtle differences in the topology of the binding sites and a lack of sequence identity in the beta-strands that comprise the core of the dockerin binding site explain why Type I and Type II cohesins display such distinct specificities for their target dockerins.

PubMed: 15913653
DOI: 10.1016/J.JMB.2005.04.037

Experimental method

X-RAY DIFFRACTION (1.8 Å)