View source for 2bv9


==HOW FAMILY 26 GLYCOSIDE HYDROLASES ORCHESTRATE CATALYSIS ON DIFFERENT POLYSACCHARIDES. STRUCTURE AND ACTIVITY OF A CLOSTRIDIUM THERMOCELLUM LICHENASE, CtLIC26A==
<StructureSection load='2bv9' size='340' side='right'caption='[[2bv9]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2bv9]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Acetivibrio_thermocellus Acetivibrio thermocellus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BV9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2BV9 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]] 1.5&#8491;</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=2bv9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2bv9 OCA], [https://pdbe.org/2bv9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2bv9 RCSB], [https://www.ebi.ac.uk/pdbsum/2bv9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2bv9 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GUNH_ACET2 GUNH_ACET2] This enzyme catalyzes the endohydrolysis of 1,4-beta-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans.
== 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/bv/2bv9_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=2bv9 ConSurf].
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== Publication Abstract from PubMed ==
One of the most intriguing features of the 90 glycoside hydrolase families (GHs) is the range of specificities displayed by different members of the same family, whereas the catalytic apparatus and mechanism are often invariant. Family GH26 predominantly comprises beta-1,4 mannanases; however, a bifunctional Clostridium thermocellum GH26 member (hereafter CtLic26A) displays a markedly different specificity. We show that CtLic26A is a lichenase, specific for mixed (Glcbeta1,4Glcbeta1,4Glcbeta1,3)n oligo- and polysaccharides, and displays no activity on manno-configured substrates or beta-1,4-linked homopolymers of glucose or xylose. The three-dimensional structure of the native form of CtLic26A has been solved at 1.50-A resolution, revealing a characteristic (beta/alpha)8 barrel with Glu-109 and Glu-222 acting as the catalytic acid/base and nucleophile in a double-displacement mechanism. The complex with the competitive inhibitor, Glc-beta-1,3-isofagomine (Ki 1 microm), at 1.60 A sheds light on substrate recognition in the -2 and -1 subsites and illuminates why the enzyme is specific for lichenan-based substrates. Hydrolysis of beta-mannosides by GH26 members is thought to proceed through transition states in the B2,5 (boat) conformation in which structural distinction of glucosides versus mannosides reflects not the configuration at C2 but the recognition of the pseudoaxial O3 of the B2,5 conformation. We suggest a different conformational itinerary for the GH26 enzymes active on gluco-configured substrates.

How family 26 glycoside hydrolases orchestrate catalysis on different polysaccharides: structure and activity of a Clostridium thermocellum lichenase, CtLic26A.,Taylor EJ, Goyal A, Guerreiro CI, Prates JA, Money VA, Ferry N, Morland C, Planas A, Macdonald JA, Stick RV, Gilbert HJ, Fontes CM, Davies GJ J Biol Chem. 2005 Sep 23;280(38):32761-7. Epub 2005 Jun 28. PMID:15987675<ref>PMID:15987675</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Glucanase 3D structures|Glucanase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Acetivibrio thermocellus]]
[[Category: Large Structures]]
[[Category: Davies GJ]]
[[Category: Ferry N]]
[[Category: Fontes CMGA]]
[[Category: Gilbert HJ]]
[[Category: Goyal A]]
[[Category: Guerreiro CIPD]]
[[Category: Macdonald JA]]
[[Category: Money VA]]
[[Category: Morland C]]
[[Category: Planas A]]
[[Category: Prates JAM]]
[[Category: Stick RV]]
[[Category: Taylor EJ]]