5NGL

The endo-beta1,6-glucanase BT3312


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.188 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A Bacteroidetes locus dedicated to fungal 1,6-beta-glucan degradation: Unique substrate conformation drives specificity of the key endo-1,6-beta-glucanase.

Temple, M.J.Cuskin, F.Basle, A.Hickey, N.Speciale, G.Williams, S.J.Gilbert, H.J.Lowe, E.C.

(2017) J. Biol. Chem. 292: 10639-10650

  • DOI: 10.1074/jbc.M117.787606
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Glycans are major nutrients available to the human gut microbiota. The Bacteroides are generalist glycan degraders, and this function is mediated largely by polysaccharide utilization loci (PULs). The genomes of several Bacteroides species contain a ...

    Glycans are major nutrients available to the human gut microbiota. The Bacteroides are generalist glycan degraders, and this function is mediated largely by polysaccharide utilization loci (PULs). The genomes of several Bacteroides species contain a PUL, PUL1,6-β-glucan, that was predicted to target mixed linked plant 1,3;1,4-β-glucans. To test this hypothesis we characterized the proteins encoded by this locus in Bacteroides thetaiotaomicron, a member of the human gut microbiota. We show here that PUL1,6-β-glucan does not orchestrate the degradation of a plant polysaccharide but targets a fungal cell wall glycan, 1,6-β-glucan, which is a growth substrate for the bacterium. The locus is up-regulated by 1,6-β-glucan and encodes two enzymes, a surface endo-1,6-β-glucanase, BT3312, and a periplasmic β-glucosidase that targets primarily 1,6-β-glucans. The non-catalytic proteins encoded by PUL1,6-β-glucan target 1,6-β-glucans and comprise a surface glycan-binding protein and a SusD homologue that delivers glycans to the outer membrane transporter. We identified the central role of the endo-1,6-β-glucanase in 1,6-β-glucan depolymerization by deleting bt3312, which prevented the growth of B. thetaiotaomicron on 1,6-β-glucan. The crystal structure of BT3312 in complex with β-glucosyl-1,6-deoxynojirimycin revealed a TIM barrel catalytic domain that contains a deep substrate-binding cleft tailored to accommodate the hook-like structure adopted by 1,6-β-glucan. Specificity is driven by the complementarity of the enzyme active site cleft and the conformation of the substrate. We also noted that PUL1,6-β-glucan is syntenic to many PULs from other Bacteroidetes, suggesting that utilization of yeast and fungal cell wall 1,6-β-glucans is a widespread adaptation within the human microbiota.


    Organizational Affiliation

    From the Institute of Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE4 2HH, United Kingdom and.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glucosylceramidase
A, B, C
494Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / NCTC 10582 / E50 / VPI-5482)Mutation(s): 0 
Find proteins for Q8A2J3 (Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / NCTC 10582 / E50 / VPI-5482))
Go to UniProtKB:  Q8A2J3
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
B
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
BGC
Query on BGC

Download SDF File 
Download CCD File 
A, B, C
BETA-D-GLUCOSE
C6 H12 O6
WQZGKKKJIJFFOK-VFUOTHLCSA-N
 Ligand Interaction
NOJ
Query on NOJ

Download SDF File 
Download CCD File 
A, B, C
1-DEOXYNOJIRIMYCIN
MORANOLINE
C6 H13 N O4
LXBIFEVIBLOUGU-JGWLITMVSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.188 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 62.379α = 90.00
b = 78.766β = 94.94
c = 145.526γ = 90.00
Software Package:
Software NamePurpose
ARPmodel building
Cootmodel building
WARPmodel building
PHASERphasing
XDSdata reduction
REFMACrefinement
Aimlessdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Wellcome TrustUnited KingdomWT097907MA

Revision History 

  • Version 1.0: 2017-05-10
    Type: Initial release
  • Version 1.1: 2017-05-17
    Type: Database references
  • Version 1.2: 2017-07-05
    Type: Database references