View source for 9b87


==Tetrameric cryo-EM structure of E. coli BcsZ==
<StructureSection load='9b87' size='340' side='right'caption='[[9b87]], [[Resolution|resolution]] 2.65&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9b87]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9B87 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9B87 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.65&#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=9b87 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9b87 OCA], [https://pdbe.org/9b87 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9b87 RCSB], [https://www.ebi.ac.uk/pdbsum/9b87 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9b87 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 ==
Phosphoethanolamine (pEtN) cellulose is a naturally occurring modified cellulose produced by several Enterobacteriaceae. The minimal components of the E. coli cellulose synthase complex include the catalytically active BcsA enzyme, a hexameric semicircle of the periplasmic BcsB protein, and the outer membrane (OM)-integrated BcsC subunit containing periplasmic tetratricopeptide repeats (TPR). Additional subunits include BcsG, a membrane-anchored periplasmic pEtN transferase associated with BcsA, and BcsZ, a periplasmic cellulase of unknown biological function. While cellulose synthesis and translocation by BcsA are well described, little is known about its pEtN modification and translocation across the cell envelope. We show that the N-terminal cytosolic domain of BcsA positions three BcsG copies near the nascent cellulose polymer. Further, the semicircle's terminal BcsB subunit tethers the N-terminus of a single BcsC protein in a trans-envelope secretion system. BcsC's TPR motifs bind a putative cello-oligosaccharide near the entrance to its OM pore. Additionally, we show that only the hydrolytic activity of BcsZ but not the subunit itself is necessary for cellulose secretion, suggesting a secretion mechanism based on enzymatic removal of translocation incompetent cellulose. Lastly, protein engineering introduces cellulose pEtN modification in orthogonal cellulose biosynthetic systems. These findings advance our understanding of pEtN cellulose modification and secretion.

Insights into phosphoethanolamine cellulose synthesis and secretion across the Gram-negative cell envelope.,Verma P, Ho R, Chambers SA, Cegelski L, Zimmer J Nat Commun. 2024 Sep 6;15(1):7798. doi: 10.1038/s41467-024-51838-0. PMID:39242554<ref>PMID:39242554</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9b87" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Verma P]]
[[Category: Zimmer J]]