Crystal structure of the bacterial cellulose synthase subunit G (BcsG) catalytic domain from Escherichia coli, selenomethionine variant

Experimental Data Snapshot

  • Resolution: 1.44 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.197 

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TheEscherichia colicellulose synthase subunit G (BcsG) is a Zn2+-dependent phosphoethanolamine transferase.

Anderson, A.C.Burnett, A.J.N.Hiscock, L.Maly, K.E.Weadge, J.T.

(2020) J Biol Chem 295: 6225-6235

  • DOI: https://doi.org/10.1074/jbc.RA119.011668
  • Primary Citation of Related Structures:  
    6PCZ, 6PD0

  • PubMed Abstract: 

    Bacterial biofilms are cellular communities that produce an adherent matrix. Exopolysaccharides are key structural components of this matrix and are required for the assembly and architecture of biofilms produced by a wide variety of microorganisms. The human bacterial pathogens Escherichia coli and Salmonella enterica produce a biofilm matrix composed primarily of the exopolysaccharide phosphoethanolamine (pEtN) cellulose. Once thought to be composed of only underivatized cellulose, the pEtN modification present in these matrices has been implicated in the overall architecture and integrity of the biofilm. However, an understanding of the mechanism underlying pEtN derivatization of the cellulose exopolysaccharide remains elusive. The bacterial cellulose synthase subunit G (BcsG) is a predicted inner membrane-localized metalloenzyme that has been proposed to catalyze the transfer of the pEtN group from membrane phospholipids to cellulose. Here we present evidence that the C-terminal domain of BcsG from E. coli ( Ec BcsG ΔN ) functions as a phosphoethanolamine transferase in vitro with substrate preference for cellulosic materials. Structural characterization of Ec BcsG ΔN revealed that it belongs to the alkaline phosphatase superfamily, contains a Zn 2+ ion at its active center, and is structurally similar to characterized enzymes that confer colistin resistance in Gram-negative bacteria. Informed by our structural studies, we present a functional complementation experiment in E. coli AR3110, indicating that the activity of the BcsG C-terminal domain is essential for integrity of the pellicular biofilm. Furthermore, our results established a similar but distinct active-site architecture and catalytic mechanism shared between BcsG and the colistin resistance enzymes.

  • Organizational Affiliation

    Department of Biology, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cellulose biosynthesis protein BcsG
A, B
417Escherichia coli K-12Mutation(s): 0 
Gene Names: bcsGyhjUb3538JW3506
Find proteins for P37659 (Escherichia coli (strain K12))
Explore P37659 
Go to UniProtKB:  P37659
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP37659
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
A, B
Experimental Data & Validation

Experimental Data

  • Resolution: 1.44 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.197 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.71α = 90
b = 94.58β = 90
c = 105.19γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Natural Sciences and Engineering Research Council (NSERC, Canada)Canada630044

Revision History  (Full details and data files)

  • Version 1.0: 2020-03-18
    Type: Initial release
  • Version 1.1: 2020-05-13
    Changes: Database references