InterPro domain: IPR027443

Isopenicillin N synthase (IPNS) catalyses conversion of the linear tripeptide delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (ACV) to isopenicillin N (IPN), the central step in biosynthesis of the beta-lactam antibiotics [ 1 ]. IPNS is a nonhaem-Fe2+-dependent enzyme. It belongs to a class of nonhaem Fe2+-containing enzymes which includes 2-oxoglutarate-dependent dioxygenases, 2-oxoglutarate-dependent hydroxy- lases, and enzymes involved in ethylene formation and anthocyaninidin biosynthesis.

The IPNS structure shows that the active site is buried within the hydrophobic pocket of an eight-stranded jelly roll barrel [ 2 , 3 ].

1. The mechanism for isopenicillin N synthase from density-functional modeling highlights the similarities with other enzymes in the 2-His-1-carboxylate family. Biochemistry 47, 1031-42
2. Crystallographic studies on the reaction of isopenicillin N synthase with an unsaturated substrate analogue. Org. Biomol. Chem. 1, 1455-60
3. Recent advances in the structure and function of isopenicillin N synthase. Antonie Van Leeuwenhoek 75, 33-9