2Y6F

Isopenicillin N synthase with AC-D-S-methyl-3R-methylcysteine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.79 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.176 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Isopenicillin N Synthase Binds Delta-(L-Alpha-Aminoadipoyl)-L-Cysteinyl-D-Thia-Allo-Isoleucine Through Both Sulfur Atoms.

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

(2011) Chembiochem 12: 1881

  • DOI: 10.1002/cbic.201100149

  • PubMed Abstract: 
  • Isopenicillin N synthase (IPNS) catalyses the synthesis of isopenicillin N (IPN), the biosynthetic precursor to penicillin and cephalosporin antibiotics. IPNS is a non-heme iron(II) oxidase that mediates the oxidative cyclisation of the tripeptide δ- ...

    Isopenicillin N synthase (IPNS) catalyses the synthesis of isopenicillin N (IPN), the biosynthetic precursor to penicillin and cephalosporin antibiotics. IPNS is a non-heme iron(II) oxidase that mediates the oxidative cyclisation of the tripeptide δ-L-α-aminoadipoyl-L-cysteinyl-D-valine (ACV) to IPN with a concomitant reduction of molecular oxygen to water. Solution-phase incubation experiments have shown that, although IPNS can turn over analogues with a diverse range of hydrocarbon side chains in the third (valinyl) position of its substrate, the enzyme is much less tolerant of polar residues in this position. Thus, although IPNS converts δ-L-α-aminoadipoyl-L-cysteinyl-D-isoleucine (ACI) and AC-D-allo-isoleucine (ACaI) to penam products, the isosteric sulfur-containing peptides AC-D-thiaisoleucine (ACtI) and AC-D-thia-allo-isoleucine (ACtaI) are not turned over. To determine why these peptides are not substrates, we crystallized ACtaI with IPNS. We report the synthesis of ACtaI and the crystal structure of the IPNS:Fe(II) :ACtaI complex to 1.79 Å resolution. This structure reveals direct ligation of the thioether side chain to iron: the sulfide sulfur sits 2.66 Å from the metal, squarely in the oxygen binding site. This result articulates a structural basis for the failure of IPNS to turn over these substrates.


    Organizational Affiliation

    Chemistry Research Laboratory, University of Oxford, 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)Mutation(s): 0 
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 3 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
M9F
Query on M9F

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Download CCD File 
A
(2S)-2-AMINO-6-[[(2R)-1-[[(2S)-1-HYDROXY-3-METHYLSULFANYL-1-OXO-BUTAN-2-YL]AMINO]-1-OXO-3-SULFANYL-PROPAN-2-YL]AMINO]-6-OXO-HEXANOIC ACID
C14 H25 N3 O6 S2
STWWPNPLTMLLPP-FTYOSLGDSA-N
 Ligand Interaction
FE
Query on FE

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Download CCD File 
A
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.79 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.176 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 47.396α = 90.00
b = 73.349β = 90.00
c = 102.476γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
REFMACrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-08-31
    Type: Initial release
  • Version 1.1: 2017-07-05
    Type: Refinement description