Download MendeleyThe Crystal Structure of an Isopenicillin N Synthase Complex with an Ethereal Substrate Analogue Reveals Water in the Oxygen Binding Site.
Clifton, I.J., Ge, W., Adlington, R.M., Baldwin, J.E., Rutledge, P.J.(2013) FEBS Lett 587: 2705
- PubMed: 23860486
- DOI: https://doi.org/10.1016/j.febslet.2013.07.016
- Primary Citation of Related Structures:
3ZOI - PubMed Abstract:
Isopenicillin N synthase (IPNS) is a non-heme iron oxidase central to the biosynthesis of β-lactam antibiotics. IPNS converts the tripeptide δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine (ACV) to isopenicillin N while reducing molecular oxygen to water. The substrate analogue δ-(L-α-aminoadipoyl)-L-cysteinyl-O-methyl-D-threonine (ACmT) is not turned over by IPNS. Epimeric δ-(L-α-aminoadipoyl)-L-cysteinyl-O-methyl-D-allo-threonine (ACmaT) is converted to a bioactive penam product. ACmT and ACmaT differ from each other only in the stereochemistry at the β-carbon atom of their third residue. These substrates both contain a methyl ether in place of the isopropyl group of ACV. We report an X-ray crystal structure for the anaerobic IPNS:Fe(II):ACmT complex. This structure reveals an additional water molecule bound to the active site metal, held by hydrogen-bonding to the ether oxygen atom of the substrate analogue.
Organizational Affiliation:
Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
