8QF2 | pdb_00008qf2

Beta-L-Arabinofurano-cyclitol Aziridines are Cysteine-directed Broad-spectrum Inhibitors and Activity-based Probes for Retaining Beta-L-arabinofuranosidases


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 
    0.254 (Depositor), 0.257 (DCC) 
  • R-Value Work: 
    0.207 (Depositor), 0.210 (DCC) 
  • R-Value Observed: 
    0.209 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

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Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history

Literature

beta-l- Arabino furano-cyclitol Aziridines Are Covalent Broad-Spectrum Inhibitors and Activity-Based Probes for Retaining beta-l-Arabinofuranosidases.

Borlandelli, V.Offen, W.Moroz, O.Nin-Hill, A.McGregor, N.Binkhorst, L.Ishiwata, A.Armstrong, Z.Artola, M.Rovira, C.Davies, G.J.Overkleeft, H.S.

(2023) ACS Chem Biol 18: 2564-2573

  • DOI: https://doi.org/10.1021/acschembio.3c00558
  • Primary Citation Related Structures: 
    8QF2, 8QF8

  • PubMed Abstract: 

    GH127 and GH146 microorganismal retaining β-l-arabinofuranosidases, expressed by human gut microbiomes, feature an atypical catalytic domain and an unusual mechanism of action. We recently reported that both Bacteroides thetaiotaomicron Bt GH146 and Bifidobacterium longum HypBA1 are inhibited by β-l- arabino furanosyl cyclophellitol epoxide, supporting the action of a zinc-coordinated cysteine as a catalytic nucleophile, where in most retaining GH families, an aspartate or glutamate is employed. This work presents a panel of β-l- arabino furanosyl cyclophellitol epoxides and aziridines as mechanism-based Bt GH146/HypBA1 inhibitors and activity-based probes. The β-l- arabino furanosyl cyclophellitol aziridines both inhibit and label β-l-arabinofuranosidase efficiently (however with different activities), whereas the epoxide-derived probes favor Bt GH146 over HypBA1. These findings are accompanied by X-ray structural analysis of the unmodified β-l- arabino furanosyl cyclophellitol aziridine in complex with both isozymes, which were shown to react by nucleophilic opening of the aziridine, at the pseudoanomeric carbon, by the active site cysteine nucleophile to form a stable thioether bond. Altogether, our activity-based probes may serve as chemical tools for the detection and identification of low-abundance β-l-arabinofuranosidases in complex biological samples.


  • Organizational Affiliation
    • Bio-organic Synthesis, Leiden Institute of Chemistry (LIC), Leiden University, Gorlaeus Laboratories, Einsteinweg 55, 2333 CC Leiden, The Netherlands.

Macromolecule Content 

  • Total Structure Weight: 74.67 kDa 
  • Atom Count: 5,181 
  • Modeled Residue Count: 657 
  • Deposited Residue Count: 669 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Non-reducing end beta-L-arabinofuranosidase669Bifidobacterium longumMutation(s): 0 
Gene Names: hypBA1
EC: 3.2.1.185
UniProt
Find proteins for E8MGH8 (Bifidobacterium longum subsp. longum (strain ATCC 15707 / DSM 20219 / JCM 1217 / NCTC 11818 / E194b))
Explore E8MGH8 
Go to UniProtKB:  E8MGH8
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupE8MGH8
Sequence Annotations
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Reference Sequence

Small Molecules

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free:  0.254 (Depositor), 0.257 (DCC) 
  • R-Value Work:  0.207 (Depositor), 0.210 (DCC) 
  • R-Value Observed: 0.209 (Depositor) 
Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 77.26α = 90
b = 77.26β = 90
c = 254.647γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XSCALEdata scaling
REFMACphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
European Research Council (ERC)European Union951231

Revision History  (Full details and data files)

  • Version 1.0: 2023-12-13
    Type: Initial release
  • Version 1.1: 2023-12-27
    Changes: Database references
  • Version 1.2: 2024-11-06
    Changes: Structure summary