Structure of wild type A. niger Fdc1 purified in the dark with prFMN in the iminium form

Experimental Data Snapshot

  • Resolution: 1.14 Å
  • R-Value Free: 0.167 
  • R-Value Work: 0.149 
  • R-Value Observed: 0.150 

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The role of conserved residues in Fdc decarboxylase in prenylated flavin mononucleotide oxidative maturation, cofactor isomerization, and catalysis.

Bailey, S.S.Payne, K.A.P.Fisher, K.Marshall, S.A.Cliff, M.J.Spiess, R.Parker, D.A.Rigby, S.E.J.Leys, D.

(2018) J Biol Chem 293: 2272-2287

  • DOI: https://doi.org/10.1074/jbc.RA117.000881
  • Primary Citation of Related Structures:  
    6EV3, 6EV4, 6EV5, 6EV6, 6EV7, 6EV8, 6EV9, 6EVA, 6EVB, 6EVC, 6EVD, 6EVE, 6EVF

  • PubMed Abstract: 

    The UbiD family of reversible decarboxylases act on aromatic, heteroaromatic, and unsaturated aliphatic acids and utilize a prenylated flavin mononucleotide (prFMN) as cofactor, bound adjacent to a conserved Glu-Arg-Glu/Asp ionic network in the enzyme's active site. It is proposed that UbiD activation requires oxidative maturation of the cofactor, for which two distinct isomers, prFMN ketimine and prFMN iminium , have been observed. It also has been suggested that only the prFMN iminium form is relevant to catalysis, which requires transient cycloaddition between substrate and cofactor. Using Aspergillus niger Fdc1 as a model system, we reveal that isomerization of prFMN iminium to prFMN ketimine is a light-dependent process that is largely independent of the Glu 277 -Arg 173 -Glu 282 network and accompanied by irreversible loss of activity. On the other hand, efficient catalysis was highly dependent on an intact Glu-Arg-Glu network, as only Glu → Asp substitutions retain activity. Surprisingly, oxidative maturation to form the prFMN iminium species is severely affected only for the R173A variant. In summary, the unusual irreversible isomerization of prFMN is light-dependent and probably proceeds via high-energy intermediates but is independent of the Glu-Arg-Glu network. Our results from mutagenesis, crystallographic, spectroscopic, and kinetic experiments indicate a clear role for the Glu-Arg-Glu network in both catalysis and oxidative maturation.

  • Organizational Affiliation

    From the Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, M1 7DN, United Kingdom and david.leys@manchester.ac.uk.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Ferulic acid decarboxylase 1508Aspergillus niger CBS 513.88Mutation(s): 0 
Gene Names: fdc1An03g06590
Find proteins for A2QHE5 (Aspergillus niger (strain ATCC MYA-4892 / CBS 513.88 / FGSC A1513))
Explore A2QHE5 
Go to UniProtKB:  A2QHE5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA2QHE5
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on 4LU

Download Ideal Coordinates CCD File 
B [auth A]1-deoxy-5-O-phosphono-1-(3,3,4,5-tetramethyl-9,11-dioxo-2,3,8,9,10,11-hexahydro-7H-quinolino[1,8-fg]pteridin-12-ium-7-y l)-D-ribitol
C22 H30 N4 O9 P
Query on MN

Download Ideal Coordinates CCD File 
Query on K

Download Ideal Coordinates CCD File 
D [auth A],
E [auth A]
Experimental Data & Validation

Experimental Data

  • Resolution: 1.14 Å
  • R-Value Free: 0.167 
  • R-Value Work: 0.149 
  • R-Value Observed: 0.150 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 95.97α = 90
b = 64.03β = 90
c = 87.63γ = 90
Software Package:
Software NamePurpose
xia2data reduction
xia2data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Biotechnology and Biological Sciences Research CouncilUnited Kingdom--

Revision History  (Full details and data files)

  • Version 1.0: 2017-12-27
    Type: Initial release
  • Version 1.1: 2018-01-03
    Changes: Database references
  • Version 1.2: 2018-01-31
    Changes: Author supporting evidence
  • Version 1.3: 2018-02-28
    Changes: Database references