View source for 3qxf


==Structure of the bacterial cellulose synthase subunit Z==
<StructureSection load='3qxf' size='340' side='right'caption='[[3qxf]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3qxf]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3QXF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3QXF 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]] 1.85&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=3qxf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3qxf OCA], [https://pdbe.org/3qxf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3qxf RCSB], [https://www.ebi.ac.uk/pdbsum/3qxf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3qxf ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GUN_ECOLI GUN_ECOLI] Hydrolyzes carboxymethylcellulose.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Cellulose, a very abundant extracellular polysaccharide, is synthesized in a finely tuned process that involves the activity of glycosyl-transferases and hydrolases. The cellulose microfibril consists of bundles of linear beta-1,4-glucan chains that are synthesized inside the cell; however, the mechanism by which these polymers traverse the cell membrane is currently unknown. In Gram-negative bacteria, the cellulose synthase complex forms a trans-envelope complex consisting of at least four subunits. Although three of these subunits account for the synthesis and translocation of the polysaccharide, the fourth subunit, BcsZ, is a periplasmic protein with endo-beta-1,4-glucanase activity. BcsZ belongs to family eight of glycosyl-hydrolases, and its activity is required for optimal synthesis and membrane translocation of cellulose. In this study we report two crystal structures of BcsZ from Escherichia coli. One structure shows the wild-type enzyme in its apo form, and the second structure is for a catalytically inactive mutant of BcsZ in complex with the substrate cellopentaose. The structures demonstrate that BcsZ adopts an (alpha/alpha)(6)-barrel fold and that it binds four glucan moieties of cellopentaose via highly conserved residues exclusively on the nonreducing side of its catalytic center. Thus, the BcsZ-cellopentaose structure most likely represents a posthydrolysis state in which the newly formed nonreducing end has already left the substrate binding pocket while the enzyme remains attached to the truncated polysaccharide chain. We further show that BcsZ efficiently degrades beta-1,4-glucans in in vitro cellulase assays with carboxymethyl-cellulose as substrate.

Apo- and cellopentaose-bound structures of the bacterial cellulose synthase subunit BcsZ.,Mazur O, Zimmer J J Biol Chem. 2011 May 20;286(20):17601-6. Epub 2011 Mar 25. PMID:21454578<ref>PMID:21454578</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3qxf" style="background-color:#fffaf0;"></div>

==See Also==
*[[Glucanase 3D structures|Glucanase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Zimmer J]]