6ER4

Ruminococcus gnavus IT-sialidase CBM40 bound to alpha2,6 sialyllactose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.30 Å
  • R-Value Free: 0.135 
  • R-Value Work: 0.108 
  • R-Value Observed: 0.110 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Unravelling the specificity and mechanism of sialic acid recognition by the gut symbiont Ruminococcus gnavus.

Owen, C.D.Tailford, L.E.Monaco, S.Suligoj, T.Vaux, L.Lallement, R.Khedri, Z.Yu, H.Lecointe, K.Walshaw, J.Tribolo, S.Horrex, M.Bell, A.Chen, X.Taylor, G.L.Varki, A.Angulo, J.Juge, N.

(2017) Nat Commun 8: 2196-2196

  • DOI: https://doi.org/10.1038/s41467-017-02109-8
  • Primary Citation of Related Structures:  
    6ER2, 6ER3, 6ER4

  • PubMed Abstract: 

    Ruminococcus gnavus is a human gut symbiont wherein the ability to degrade mucins is mediated by an intramolecular trans-sialidase (RgNanH). RgNanH comprises a GH33 catalytic domain and a sialic acid-binding carbohydrate-binding module (CBM40). Here we used glycan arrays, STD NMR, X-ray crystallography, mutagenesis and binding assays to determine the structure and function of RgNanH_CBM40 (RgCBM40). RgCBM40 displays the canonical CBM40 β-sandwich fold and broad specificity towards sialoglycans with millimolar binding affinity towards α2,3- or α2,6-sialyllactose. RgCBM40 binds to mucus produced by goblet cells and to purified mucins, providing direct evidence for a CBM40 as a novel bacterial mucus adhesin. Bioinformatics data show that RgCBM40 canonical type domains are widespread among Firmicutes. Furthermore, binding of R. gnavus ATCC 29149 to intestinal mucus is sialic acid mediated. Together, this study reveals novel features of CBMs which may contribute to the biogeography of symbiotic bacteria in the gut.


  • Organizational Affiliation

    Biomolecular Sciences Building, University of St Andrews, St Andrews, KY16 9ST, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
BNR/Asp-box repeat protein
A, B
194Mediterraneibacter gnavus ATCC 29149Mutation(s): 0 
Gene Names: RUMGNA_02694
UniProt
Find proteins for A7B557 (Mediterraneibacter gnavus (strain ATCC 29149 / DSM 114966 / JCM 6515 / VPI C7-9))
Explore A7B557 
Go to UniProtKB:  A7B557
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA7B557
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
N-acetyl-alpha-neuraminic acid-(2-6)-beta-D-galactopyranose-(1-4)-beta-D-glucopyranose
C, D
3N/A
Glycosylation Resources
GlyTouCan:  G28868ZC
GlyCosmos:  G28868ZC
GlyGen:  G28868ZC
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.30 Å
  • R-Value Free: 0.135 
  • R-Value Work: 0.108 
  • R-Value Observed: 0.110 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 48.74α = 90
b = 72.2β = 103.88
c = 51.41γ = 90
Software Package:
Software NamePurpose
SCALAdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Biotechnology and Biological Sciences Research CouncilUnited KingdomBB/F016778/1

Revision History  (Full details and data files)

  • Version 1.0: 2018-05-02
    Type: Initial release
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Author supporting evidence, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2024-01-17
    Changes: Data collection, Database references, Refinement description, Structure summary