2VBB

Isopenicillin N synthase with substrate analogue ACOMP (35minutes oxygen exposure)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.172 
  • R-Value Work: 0.151 
  • R-Value Observed: 0.152 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Isopenicillin N Synthase Mediates Thiolate Oxidation to Sulfenate in a Depsipeptide Substrate Analogue: Implications for Oxygen Binding and a Link to Nitrile Hydratase?

Ge, W.Clifton, I.J.Stok, J.E.Adlington, R.M.Baldwin, J.E.Rutledge, P.J.

(2008) J Am Chem Soc 130: 10096

  • DOI: 10.1021/ja8005397
  • Primary Citation of Related Structures:  
    2VAU, 2VBB

  • PubMed Abstract: 
  • Isopenicillin N synthase (IPNS) is a nonheme iron oxidase that catalyzes the central step in the biosynthesis of beta-lactam antibiotics: oxidative cyclization of the linear tripeptide delta-L-alpha-aminoadipoyl-L-cysteinyl-D-valine (ACV) to isopenicillin N (IPN) ...

    Isopenicillin N synthase (IPNS) is a nonheme iron oxidase that catalyzes the central step in the biosynthesis of beta-lactam antibiotics: oxidative cyclization of the linear tripeptide delta-L-alpha-aminoadipoyl-L-cysteinyl-D-valine (ACV) to isopenicillin N (IPN). The ACV analogue delta-L-alpha-aminoadipoyl-L-cysteine (1-(S)-carboxy-2-thiomethyl)ethyl ester (ACOmC) has been synthesized as a mechanistic probe of IPNS catalysis and crystallized with the enzyme. The crystal structure of the anaerobic IPNS/Fe(II)/ACOmC complex was determined to 1.80 A resolution, revealing a highly congested active site region. By exposing these anaerobically grown crystals to high-pressure oxygen gas, an unexpected sulfenate product has been observed, complexed to iron within the IPNS active site. A mechanism is proposed for formation of the sulfenate-iron complex, and it appears that ACOmC follows a different reaction pathway at the earliest stages of its reaction with IPNS. Thus it seems that oxygen (the cosubstrate) binds in a different site to that observed in previous studies with IPNS, displacing a water ligand from iron in the process. The iron-mediated conversion of metal-bound thiolate to sulfenate has not previously been observed in crystallographic studies with IPNS. This mode of reactivity is of particular interest when considered in the context of another family of nonheme iron enzymes, the nitrile hydratases, in which post-translational oxidation of two cysteine thiolates to sulfenic and sulfinic acids is essential for enzyme activity.


    Organizational Affiliation

    Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ISOPENICILLIN N SYNTHETASEA331Aspergillus nidulansMutation(s): 0 
EC: 1.21.3.1
Find proteins for P05326 (Emericella nidulans (strain FGSC A4 / ATCC 38163 / CBS 112.46 / NRRL 194 / M139))
Explore P05326 
Go to UniProtKB:  P05326
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
VAZ
Query on VAZ

Download Ideal Coordinates CCD File 
B [auth A]N^6^-{(1R)-2-{[(1S,2R)-1-carboxy-2-hydroxy-2-(methylsulfanyl)ethyl]oxy}-1-[(oxidosulfanyl)methyl]-2-oxoethyl}-6-oxo-L-lysine
C13 H22 N2 O9 S2
CRQOTISMRKWURZ-LOSGYTSQSA-N
 Ligand Interaction
SO4
Query on SO4

Download Ideal Coordinates CCD File 
D [auth A], E [auth A]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

Download Ideal Coordinates CCD File 
F [auth A]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
FE2
Query on FE2

Download Ideal Coordinates CCD File 
C [auth A]FE (II) ION
Fe
CWYNVVGOOAEACU-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.172 
  • R-Value Work: 0.151 
  • R-Value Observed: 0.152 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 46.655α = 90
b = 71.041β = 90
c = 100.763γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
REFMACphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-07-29
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance