View source for 4x0v


==Structure of a GH5 family lichenase from Caldicellulosiruptor sp. F32==
<StructureSection load='4x0v' size='340' side='right'caption='[[4x0v]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4x0v]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Caldicellulosiruptor_sp._F32 Caldicellulosiruptor sp. F32]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4X0V OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4X0V FirstGlance]. <br>
</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=4x0v FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4x0v OCA], [https://pdbe.org/4x0v PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4x0v RCSB], [https://www.ebi.ac.uk/pdbsum/4x0v PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4x0v ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/R9RX81_9FIRM R9RX81_9FIRM] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Glycoside hydrolase (GH) family 5 is one of the largest GH families with various GH activities including lichenase, but the structural basis of the GH5 lichenase activity is still unknown. A novel thermostable lichenase F32EG5 belonging to GH5 was identified from an extremely thermophilic bacterium Caldicellulosiruptor sp. F32. F32EG5 is a bi-functional cellulose and lichenan-degrading enzyme and exhibited a high activity on beta-1,3-1,4-glucan but side activity on cellulose. Thin-layer chromatography and NMR analyses indicated that F32EG5 cleaved the beta-1,4 linkage or the beta-1,3 linkage while a 4- O -substitued glucose residue linked to a glucose residue through a beta-1,3 linkage, which is completely different from extensively studied GH16 lichenase that catalyses strict endo-hydrolysis of the beta-1,4-glycosidic linkage adjacent to a 3- O -substitued glucose residue in the mixed linked beta-glucans. The crystal structure of F32EG5 was determined to 2.8 A resolution and the crystal structure of the complex of F32EG5 E193Q mutant and cellotetraose was determined to 1.7 A resolution, which revealed that the exit subsites of substrate binding sites contribute to both thermostability and substrate specificity of F32EG5. The sugar chain showed a sharp bend in the complex structure, suggesting that a substrate cleft fitting to the bent sugar chains in lichenan is a common feature of GH5 lichenases. The mechanism of thermostability and substrate selectivity of F32EG5 was further demonstrated by molecular dynamics simulation and site-directed mutagenesis. These results provide biochemical and structural insight into thermostability and substrate selectivity of GH5 lichenases which have potential in industrial processes.

Structural Insights into the Substrate Specificity of a Glycoside Hydrolase Family 5 Lichenase from Caldicellulosiruptor sp. F32.,Meng DD, Liu X, Dong S, Wang YF, Ma XQ, Zhou H, Wang X, Yao LS, Feng Y, Li FL Biochem J. 2017 Aug 24. pii: BCJ20170328. doi: 10.1042/BCJ20170328. PMID:28838949<ref>PMID:28838949</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 4x0v" style="background-color:#fffaf0;"></div>

==See Also==
*[[Glucanase 3D structures|Glucanase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Caldicellulosiruptor sp. F32]]
[[Category: Large Structures]]
[[Category: Feng Y]]
[[Category: Li F]]
[[Category: Liu X]]
[[Category: Meng D]]
[[Category: Wang X]]