4JH9

Crystal Structure of FosB from Bacillus cereus with Maganese and Potential BSH-Fosfomycin Product


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.77 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.186 

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This is version 1.3 of the entry. See complete history


Literature

Structural and Chemical Aspects of Resistance to the Antibiotic Fosfomycin Conferred by FosB from Bacillus cereus.

Thompson, M.K.Keithly, M.E.Harp, J.Cook, P.D.Jagessar, K.L.Sulikowski, G.A.Armstrong, R.N.

(2013) Biochemistry 52: 7350-7362

  • DOI: https://doi.org/10.1021/bi4009648
  • Primary Citation of Related Structures:  
    4JH1, 4JH2, 4JH3, 4JH4, 4JH5, 4JH6, 4JH7, 4JH8, 4JH9

  • PubMed Abstract: 

    The fosfomycin resistance enzymes, FosB, from Gram-positive organisms, are M(2+)-dependent thiol tranferases that catalyze nucleophilic addition of either L-cysteine (L-Cys) or bacillithiol (BSH) to the antibiotic, resulting in a modified compound with no bacteriacidal properties. Here we report the structural and functional characterization of FosB from Bacillus cereus (FosB(Bc)). The overall structure of FosB(Bc), at 1.27 Å resolution, reveals that the enzyme belongs to the vicinal oxygen chelate (VOC) superfamily. Crystal structures of FosB(Bc) cocrystallized with fosfomycin and a variety of divalent metals, including Ni(2+), Mn(2+), Co(2+), and Zn(2+), indicate that the antibiotic coordinates to the active site metal center in an orientation similar to that found in the structurally homologous manganese-dependent fosfomycin resistance enzyme, FosA. Surface analysis of the FosB(Bc) structures show a well-defined binding pocket and an access channel to C1 of fosfomycin, the carbon to which nucleophilic addition of the thiol occurs. The pocket and access channel are appropriate in size and shape to accommodate L-Cys or BSH. Further investigation of the structures revealed that the fosfomycin molecule, anchored by the metal, is surrounded by a cage of amino acids that hold the antibiotic in an orientation such that C1 is centered at the end of the solvent channel, positioning the compound for direct nucleophilic attack by the thiol substrate. In addition, the structures of FosB(Bc) in complex with the L-Cys-fosfomycin product (1.55 Å resolution) and in complex with the bacillithiol-fosfomycin product (1.77 Å resolution) coordinated to a Mn(2+) metal in the active site have been determined. The L-Cys moiety of either product is located in the solvent channel, where the thiol has added to the backside of fosfomycin C1 located at the end of the channel. Concomitant kinetic analyses of FosB(Bc) indicated that the enzyme has a preference for BSH over L-Cys when activated by Mn(2+) and is inhibited by Zn(2+). The fact that Zn(2+) is an inhibitor of FosB(Bc) was used to obtain a ternary complex structure of the enzyme with both fosfomycin and L-Cys bound.


  • Organizational Affiliation

    Department of Biochemistry, Vanderbilt University , Nashville, Tennessee 37232, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Metallothiol transferase FosB
A, B
138Bacillus cereus ATCC 10987Mutation(s): 0 
Gene Names: fosBBCE_2111
EC: 2.5.1
UniProt
Find proteins for Q739M9 (Bacillus cereus (strain ATCC 10987 / NRS 248))
Explore Q739M9 
Go to UniProtKB:  Q739M9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ739M9
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.77 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.186 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 56.475α = 90
b = 64.477β = 90
c = 83.907γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-10-02
    Type: Initial release
  • Version 1.1: 2013-12-04
    Changes: Database references
  • Version 1.2: 2018-04-18
    Changes: Data collection
  • Version 1.3: 2024-02-28
    Changes: Data collection, Database references, Derived calculations