View source for 1qbb


==BACTERIAL CHITOBIASE COMPLEXED WITH CHITOBIOSE (DINAG)==
<StructureSection load='1qbb' size='340' side='right'caption='[[1qbb]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qbb]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Serratia_marcescens Serratia marcescens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QBB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QBB 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]] 2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1qbb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qbb OCA], [https://pdbe.org/1qbb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1qbb RCSB], [https://www.ebi.ac.uk/pdbsum/1qbb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1qbb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CHB_SERMA CHB_SERMA] Digests the beta-1,4-glycosidic bonds in N-acetylglucosamine (GlcNAc) oligomers (mainly dimers).
== 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/qb/1qbb_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=1qbb ConSurf].
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== Publication Abstract from PubMed ==
Chitin, the second most abundant polysaccharide on earth, is degraded by chitinases and chitobiases. The structure of Serratia marcescens chitobiase has been refined at 1.9 A resolution. The mature protein is folded into four domains and its active site is situated at the C-terminal end of the central (beta alpha)8-barrel. Based on the structure of the complex with the substrate disaccharide chitobiose, we propose an acid-base reaction mechanism, in which only one protein carboxylate acts as catalytic acid, while the nucleophile is the polar acetamido group of the sugar in a substrate-assisted reaction. The structural data lead to the hypothesis that the reaction proceeds with retention of anomeric configuration. The structure allows us to model the catalytic domain of the homologous hexosaminidases to give a structural rationale to pathogenic mutations that underlie Tay-Sachs and Sandhoff disease.

Bacterial chitobiase structure provides insight into catalytic mechanism and the basis of Tay-Sachs disease.,Tews I, Perrakis A, Oppenheim A, Dauter Z, Wilson KS, Vorgias CE Nat Struct Biol. 1996 Jul;3(7):638-48. PMID:8673609<ref>PMID:8673609</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 1qbb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-N-acetylhexosaminidase 3D structures|Beta-N-acetylhexosaminidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Serratia marcescens]]
[[Category: Dauter Z]]
[[Category: Oppenheim A]]
[[Category: Perrakis A]]
[[Category: Tews I]]
[[Category: Vorgias CE]]
[[Category: Wilson KS]]