3ZKY

Isopenicillin N synthase with substrate analogue AhCmC


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.165 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The Interaction of Isopenicillin N Synthase with Homologated Substrate Analogues Delta-(L-Alpha-Aminoadipoyl)-L-Homocysteinyl-D-Xaa Characterised by Protein Crystallography.

Daruzzaman, A.Clifton, I.J.Adlington, R.M.Baldwin, J.E.Rutledge, P.J.

(2013) Chembiochem 14: 599

  • DOI: 10.1002/cbic.201200728
  • Primary Citation of Related Structures:  3ZKU

  • PubMed Abstract: 
  • Isopenicillin N synthase (IPNS) converts the linear tripeptide δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine (ACV) into bicyclic isopenicillin N (IPN) in the central step in the biosynthesis of penicillin and cephalosporin antibiotics. Solution-phase inc ...

    Isopenicillin N synthase (IPNS) converts the linear tripeptide δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine (ACV) into bicyclic isopenicillin N (IPN) in the central step in the biosynthesis of penicillin and cephalosporin antibiotics. Solution-phase incubation experiments have shown that IPNS turns over analogues with a diverse range of side chains in the third (valinyl) position of the substrate, but copes less well with changes in the second (cysteinyl) residue. IPNS thus converts the homologated tripeptides δ-(L-α-aminoadipoyl)-L-homocysteinyl-D-valine (AhCV) and δ-(L-α-aminoadipoyl)-L-homocysteinyl-D-allylglycine (AhCaG) into monocyclic hydroxy-lactam products; this suggests that the additional methylene unit in these substrates induces conformational changes that preclude second ring closure after initial lactam formation. To investigate this and solution-phase results with other tripeptides δ-(L-α-aminoadipoyl)-L-homocysteinyl-D-Xaa, we have crystallised AhCV and δ-(L-α-aminoadipoyl)-L-homocysteinyl-D-S-methylcysteine (AhCmC) with IPNS and solved crystal structures for the resulting complexes. The IPNS:Fe(II):AhCV complex shows diffuse electron density for several regions of the substrate, revealing considerable conformational freedom within the active site. The substrate is more clearly resolved in the IPNS:Fe(II):AhCmC complex, by virtue of thioether coordination to iron. AhCmC occupies two distinct conformations, both distorted relative to the natural substrate ACV, in order to accommodate the extra methylene group in the second residue. Attempts to turn these substrates over within crystalline IPNS using hyperbaric oxygenation give rise to product mixtures.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ISOPENICILLIN N SYNTHASE
A
331Emericella nidulans (strain FGSC A4 / ATCC 38163 / CBS 112.46 / NRRL 194 / M139)Gene Names: ipnA (ips)
EC: 1.21.3.1
Find proteins for P05326 (Emericella nidulans (strain FGSC A4 / ATCC 38163 / CBS 112.46 / NRRL 194 / M139))
Go to UniProtKB:  P05326
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
FE
Query on FE

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Download CCD File 
A
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
WT4
Query on WT4

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Download CCD File 
A
N-[(5S)-5-amino-5-carboxypentanoyl]-L-homocysteyl-S-methyl-D-cysteine
C14 H25 N3 O6 S2
QPRNCXQXRPJRSM-LPEHRKFASA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.165 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 46.705α = 90.00
b = 71.290β = 90.00
c = 100.920γ = 90.00
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-03-20
    Type: Initial release
  • Version 1.1: 2013-04-10
    Type: Database references
  • Version 1.2: 2017-07-05
    Type: Refinement description