Structure of the family GH92 alpha-mannosidase BT3130 from Bacteroides thetaiotaomicron in complex with Mannoimidazole (ManI)

Experimental Data Snapshot

  • Resolution: 2.40 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.209 

wwPDB Validation   3D Report Full Report

Ligand Structure Quality Assessment 

This is version 1.2 of the entry. See complete history


Bacteroides thetaiotaomicron generates diverse alpha-mannosidase activities through subtle evolution of a distal substrate-binding motif.

Thompson, A.J.Spears, R.J.Zhu, Y.Suits, M.D.L.Williams, S.J.Gilbert, H.J.Davies, G.J.

(2018) Acta Crystallogr D Struct Biol 74: 394-404

  • DOI: https://doi.org/10.1107/S2059798318002942
  • Primary Citation of Related Structures:  
    6F8Z, 6F90, 6F91, 6F92

  • PubMed Abstract: 

    A dominant human gut microbe, the well studied symbiont Bacteroides thetaiotaomicron (Bt), is a glyco-specialist that harbors a large repertoire of genes devoted to carbohydrate processing. Despite strong similarities among them, many of the encoded enzymes have evolved distinct substrate specificities, and through the clustering of cognate genes within operons termed polysaccharide-utilization loci (PULs) enable the fulfilment of complex biological roles. Structural analyses of two glycoside hydrolase family 92 α-mannosidases, BT3130 and BT3965, together with mechanistically relevant complexes at 1.8-2.5 Å resolution reveal conservation of the global enzyme fold and core catalytic apparatus despite different linkage specificities. Structure comparison shows that Bt differentiates the activity of these enzymes through evolution of a highly variable substrate-binding region immediately adjacent to the active site. These observations unveil a genetic/biochemical mechanism through which polysaccharide-processing bacteria can evolve new and specific biochemical activities from otherwise highly similar gene products.

  • Organizational Affiliation

    Department of Chemistry, University of York, Heslington, York YO10 5DD, England.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Alpha-1,2-mannosidase, putative
A, B, C
727Bacteroides thetaiotaomicronMutation(s): 0 
Gene Names: ERS852430_04477ERS852511_01397SAMN02910322_03319
Find proteins for Q8A325 (Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / JCM 5827 / CCUG 10774 / NCTC 10582 / VPI-5482 / E50))
Explore Q8A325 
Go to UniProtKB:  Q8A325
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8A325
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.40 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.209 
  • Space Group: P 62 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 273.666α = 90
b = 273.666β = 90
c = 189.759γ = 120
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling

Structure Validation

View Full Validation Report

Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Biotechnology and Biological Sciences Research CouncilUnited KingdomBB/G016127/1
Royal SocietyUnited KingdomKen Murray Research Professorship

Revision History  (Full details and data files)

  • Version 1.0: 2018-05-02
    Type: Initial release
  • Version 1.1: 2018-05-09
    Changes: Data collection, Database references
  • Version 1.2: 2024-01-17
    Changes: Data collection, Database references, Derived calculations, Refinement description