Alternative Oxidation by Isopenicillin N Synthase Observed by X-Ray Diffraction.
Ogle, J.M., Clifton, I.J., Rutledge, P.J., Elkins, J.M., Burzlaff, N.I., M Adlington, R., Roach, P.L., Baldwin, J.E.(2001) Chem Biol 8: 1231
- PubMed: 11755401 
- DOI: https://doi.org/10.1016/s1074-5521(01)00090-4
- Primary Citation of Related Structures:  
1HB1, 1HB2, 1HB3, 1HB4 - PubMed Abstract: 
Isopenicillin N synthase (IPNS) catalyses formation of bicyclic isopenicillin N, precursor to all penicillin and cephalosporin antibiotics, from the linear tripeptide delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine. IPNS is a non-haem iron(II)-dependent enzyme which utilises the full oxidising potential of molecular oxygen in catalysing the bicyclisation reaction. The reaction mechanism is believed to involve initial formation of the beta-lactam ring (via a thioaldehyde intermediate) to give an iron(IV)-oxo species, which then mediates closure of the 5-membered thiazolidine ring.
Organizational Affiliation: 
The Dyson Perrins Laboratory, University of Oxford, UK.