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Open data
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Basic information
Entry | ![]() | |||||||||
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Title | Tetrameric cryo-EM structure of E. coli BcsZ | |||||||||
![]() | BcsZ cryo-EM map | |||||||||
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![]() | Cellulase / Endoglucanase / GH-8 family / Carbohydrate-active enzyme / Hydrolase | |||||||||
Function / homology | ![]() cellulase / cellulase activity / cellulose catabolic process / extracellular region Similarity search - Function | |||||||||
Biological species | ![]() ![]() | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 2.65 Å | |||||||||
![]() | Verma P / Zimmer J | |||||||||
Funding support | ![]()
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![]() | ![]() Title: Insights into phosphoethanolamine cellulose synthesis and secretion across the Gram-negative cell envelope. Authors: Preeti Verma / Ruoya Ho / Schuyler A Chambers / Lynette Cegelski / Jochen Zimmer / ![]() Abstract: 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 ...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. | |||||||||
History |
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Structure visualization
Supplemental images |
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Downloads & links
-EMDB archive
Map data | ![]() | 59.5 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 16.3 KB 16.3 KB | Display Display | ![]() |
FSC (resolution estimation) | ![]() | 8.4 KB | Display | ![]() |
Images | ![]() | 191.4 KB | ||
Filedesc metadata | ![]() | 5.8 KB | ||
Others | ![]() ![]() | 59.4 MB 59.4 MB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 9b87MC ![]() 9b8aC ![]() 9b8hC ![]() 9b8iC ![]() 9b8vC M: atomic model generated by this map C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
EMDB pages | ![]() ![]() |
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Related items in Molecule of the Month |
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Map
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Annotation | BcsZ cryo-EM map | ||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.08 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Half map: Half map 2
File | emd_44334_half_map_1.map | ||||||||||||
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Annotation | Half map 2 | ||||||||||||
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Density Histograms |
-Half map: Half map 1
File | emd_44334_half_map_2.map | ||||||||||||
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Annotation | Half map 1 | ||||||||||||
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Density Histograms |
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Sample components
-Entire : Tetrameric assembly of bacterial cellulose synthase subunit Z
Entire | Name: Tetrameric assembly of bacterial cellulose synthase subunit Z |
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Components |
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-Supramolecule #1: Tetrameric assembly of bacterial cellulose synthase subunit Z
Supramolecule | Name: Tetrameric assembly of bacterial cellulose synthase subunit Z type: complex / ID: 1 / Parent: 0 / Macromolecule list: all / Details: Protein -Endoglucanase |
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Source (natural) | Organism: ![]() ![]() |
-Macromolecule #1: Endoglucanase
Macromolecule | Name: Endoglucanase / type: protein_or_peptide / ID: 1 / Number of copies: 4 / Enantiomer: LEVO / EC number: cellulase |
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Source (natural) | Organism: ![]() ![]() |
Molecular weight | Theoretical: 40.730762 KDa |
Recombinant expression | Organism: ![]() ![]() |
Sequence | String: MACTWPAWEQ FKKDYISQEG RVIDPSDARK ITTSEGQSYG MFSALAANDR AAFDNILDWT QNNLAQGSLK ERLPAWLWGK KENSKWEVL DSNSASDGDV WMAWSLLEAG RLWKEQRYTD IGSALLKRIA REEVVTVPGL GSMLLPGKVG FAEDNSWRFN P SYLPPTLA ...String: MACTWPAWEQ FKKDYISQEG RVIDPSDARK ITTSEGQSYG MFSALAANDR AAFDNILDWT QNNLAQGSLK ERLPAWLWGK KENSKWEVL DSNSASDGDV WMAWSLLEAG RLWKEQRYTD IGSALLKRIA REEVVTVPGL GSMLLPGKVG FAEDNSWRFN P SYLPPTLA QYFTRFGAPW TTLRETNQRL LLETAPKGFS PDWVRYEKDK GWQLKAEKTL ISSYDAIRVY MWVGMMPDSD PQ KARMLNR FKPMATFTEK NGYPPEKVDV ATGKAQGKGP VGFSAAMLPF LQNRDAQAVQ RQRVADNFPG SDAYYNYVLT LFG QGWDQH RFRFSTKGEL LPDWGQECAN SHLEHHHHHH UniProtKB: Endoglucanase |
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | single particle reconstruction |
Aggregation state | particle |
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Sample preparation
Buffer | pH: 8 |
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Vitrification | Cryogen name: ETHANE |
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Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K3 BIOCONTINUUM (6k x 4k) / Average electron dose: 50.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: ![]() |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 2.2 µm / Nominal defocus min: 1.0 µm |
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |