4fl4

<StructureSection load='4fl4' size='340' side='right' caption='[[4fl4]], [[Resolution|resolution]] 2.80&Aring;' scene=''>

<table><tr><td colspan='2'>[[4fl4]] is a 12 chain structure with sequence from [http://en.wikipedia.org/wiki/Clostridium_thermocellum Clostridium thermocellum]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=3p0d 3p0d]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4FL4 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4FL4 FirstGlance]. <br>

</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene><br>

<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">Cther_2220 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1515 Clostridium thermocellum]), sdbA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1515 Clostridium thermocellum]), ClothDRAFT_2952 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1515 Clostridium thermocellum])</td></tr>

<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4fl4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4fl4 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4fl4 RCSB], [http://www.ebi.ac.uk/pdbsum/4fl4 PDBsum]</span></td></tr>

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== Publication Abstract from PubMed ==

Cellulosomes are multi-enzyme complexes responsible for efficient degradation of plant cell wall polysaccharides. The non-enzymatic scaffoldin subunit provides a platform for cellulolytic enzyme binding that enhances the overall activity of the bound enzymes. Understanding the unique quaternary structural elements responsible for the enzymatic synergy of the cellulosome is hindered by the large size and inherent flexibility of these multi-protein complexes. Herein, we have used X-ray crystallography, small angle X-ray scattering (SAXS), and molecular dynamics (MD) to structurally characterize a ternary protein complex from the Clostridium thermocellum cellulosome that comprises a C-terminal trimodular fragment of the CipA scaffoldin bound to the SdbA type-II cohesin module and the type-I dockerin module from the Cel9D glycoside hydrolase. This complex represents the largest fragment of the cellulosome solved by X-ray crystallography to date and reveals two rigid domains, formed by the type-I cohesin:dockerin complex and by the X module-type-II cohesin:dockerin complex, which are separated by a 13-residue linker in an extended conformation. The type-I dockerin modules of the four structural models found in the asymmetric unit are in an alternate orientation to that previously observed, which provides further direct support for the dual mode of binding. Conserved intermolecular contacts between symmetry-related complexes were also observed and may play a role in higher order cellulosome structure. SAXS and MD simulations of the ternary complex revealed that the 13-residue intermodular linker of the scaffoldin subunit is highly dynamic in solution. These studies provide fundamental insights into modular positioning, linker flexibility, and higher order organization of the cellulosome.

 

 

[[Category: Clostridium thermocellum]]

[[Category: Adams, J J.]]

[[Category: BSGI, Montreal-Kingston Bacterial Structural Genomics Initiative.]]

[[Category: Bayer, E A.]]

[[Category: Currie, M A.]]

[[Category: Faucher, F.]]

[[Category: Jia, Z.]]

[[Category: Smith, S P.]]

[[Category: X module]]