View source for 1ocb


==Structure of the wild-type cellobiohydrolase Cel6A from Humicolas insolens in complex with a fluorescent substrate==
<StructureSection load='1ocb' size='340' side='right'caption='[[1ocb]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ocb]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Humicola_insolens Humicola insolens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OCB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1OCB FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.75&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=FLG:FLUORESCEINYLTHIOUREIDO'>FLG</scene>, <scene name='pdbligand=GDA:4-DEOXY-4-AMINO-BETA-D-GLUCOSE'>GDA</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=GTM:O1-METHYL-4-DEOXY-4-THIO-BETA-D-GLUCOSE'>GTM</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1ocb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ocb OCA], [https://pdbe.org/1ocb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ocb RCSB], [https://www.ebi.ac.uk/pdbsum/1ocb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ocb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GUX6_HUMIN GUX6_HUMIN] Plays a central role in the recycling of plant biomass. The biological conversion of cellulose to glucose generally requires three types of hydrolytic enzymes: (1) Endoglucanases which cut internal beta-1,4-glucosidic bonds; (2) Exocellobiohydrolases that cut the dissaccharide cellobiose from the non-reducing end of the cellulose polymer chain; (3) Beta-1,4-glucosidases which hydrolyze the cellobiose and other short cello-oligosaccharides to glucose.<ref>PMID:9882628</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/oc/1ocb_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1ocb ConSurf].
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== Publication Abstract from PubMed ==
The enzymatic digestion of cellulose entails intimate involvement of cellobiohydrolases, whose characteristic active-center tunnel contributes to a processive degradation of the polysaccharide. The cellobiohydrolase Cel6A displays an active site within a tunnel formed by two extended loops, which are known to open and close in response to ligand binding. Here we present five structures of wild-type and mutant forms of Cel6A from Humicola insolens in complex with nonhydrolyzable thio-oligosaccharides, at resolutions from 1.7-1.1 A, dissecting the structural accommodation of a processing substrate chain through the active center during hydrolysis. Movement of ligand is facilitated by extensive solvent-mediated interactions and through flexibility in the hydrophobic surfaces provided by a sheath of tryptophan residues.

Structural basis for ligand binding and processivity in cellobiohydrolase Cel6A from Humicola insolens.,Varrot A, Frandsen TP, von Ossowski I, Boyer V, Cottaz S, Driguez H, Schulein M, Davies GJ Structure. 2003 Jul;11(7):855-64. PMID:12842048<ref>PMID:12842048</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1ocb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cellobiohydrolase 3D structures|Cellobiohydrolase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Humicola insolens]]
[[Category: Large Structures]]
[[Category: Boyer V]]
[[Category: Davies GJ]]
[[Category: Driguez H]]
[[Category: Frandsen TP]]
[[Category: Schulein M]]
[[Category: Varrot A]]
[[Category: Von Ossowski I]]