9R4Q | pdb_00009r4q

Crystal structure of CtGH76 from Chaetomium thermophilum in complex with alpha-1,3-1,6-mannotriose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 
    0.233 (Depositor), 0.237 (DCC) 
  • R-Value Work: 
    0.197 (Depositor), 0.202 (DCC) 
  • R-Value Observed: 
    0.199 (Depositor) 

Starting Model: experimental
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Literature

Ct GH76, a Glycoside Hydrolase 76 from Chaetomium thermophilum , with Elongated Glycan-Binding Canyon.

Ruppenthal, S.R.Po-Hsun, W.Watad, M.Rosner, C.J.Vogt, M.S.Friedrich, M.Voigt, A.L.Petz, A.Gnau, P.Essen, L.O.

(2025) Int J Mol Sci 26

  • DOI: https://doi.org/10.3390/ijms26146589
  • Primary Citation of Related Structures:  
    9R4K, 9R4L, 9R4M, 9R4N, 9R4O, 9R4P, 9R4Q, 9R4R, 9R4S, 9R4T, 9R4U

  • PubMed Abstract: 

    Fungal cell walls, composed of polysaccharides and proteins, play critical roles in adaptation, cell division, and protection against environmental stress. Their polyglucan components are continuously remodeled by various types of glycosyl hydrolases (GHs) and transferases (GTs). In Saccharomyces cerevisiae and other ascomycetes, enzymes of the Dfg5 subfamily, which belong as GTs to the GH76 family, cleave an α1,4 linkage between glucosamine and mannose to facilitate covalent linkage of GPI-anchored proteins to the cell wall's polyglucans. In contrast, the functions of other fungal GH76 subfamilies are not understood. We characterized Ct GH76 from the sordariomycete Chaetomium thermophilum , a member of the Fungi/Bacteria-mixed GH76 subfamily, revealing conserved structural features and functional divergence within the GH76 family. Notably, our structural characterization by X-ray crystallography combined with glycan fragment screening indicated that Ct GH76 can recognize GPI-anchors like members of the Dfg5 subfamily but shows a broader promiscuity toward other glycans with central α1,6-mannobiose motifs due to the presence of an elongated glycan-binding canyon . These findings provide new insights into GH76 enzyme diversity and fungal cell wall maturation.


  • Organizational Affiliation

    Faculty of Chemistry, Department of Biochemistry, Philipps-University, 35043 Marburg, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Uncharacterized protein439Thermochaetoides thermophila DSM 1495Mutation(s): 0 
Gene Names: CTHT_0025410
UniProt
Find proteins for G0S5Y9 (Chaetomium thermophilum (strain DSM 1495 / CBS 144.50 / IMI 039719))
Explore G0S5Y9 
Go to UniProtKB:  G0S5Y9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupG0S5Y9
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-mannopyranose-(1-3)-alpha-D-mannopyranose-(1-6)-alpha-D-mannopyranose
B
3N/A
Glycosylation Resources
GlyTouCan:  G69739BI
GlyCosmos:  G69739BI
GlyGen:  G69739BI
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free:  0.233 (Depositor), 0.237 (DCC) 
  • R-Value Work:  0.197 (Depositor), 0.202 (DCC) 
  • R-Value Observed: 0.199 (Depositor) 
Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 107.099α = 90
b = 107.099β = 90
c = 126.544γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
German Research Foundation (DFG)GermanySFB 987

Revision History  (Full details and data files)

  • Version 1.0: 2025-07-16
    Type: Initial release
  • Version 1.1: 2025-08-06
    Changes: Database references