IUBMB Enzyme Nomenclature


Accepted name: isopenicillin-N epimerase

Reaction: isopenicillin N = penicillin N

For diagram click here.

Systematic name: penicillin-N 5-amino-5-carboxypentanoyl-epimerase

Comments: This enzyme contains pyridoxal phosphate. Epimerization at C-5 of the 5-amino-5-carboxypentanoyl group to form penicillin N is required to make a substrate for EC, deactoxycephalosporin-C synthase, to produce cephalosporins. Forms part of the penicillin biosynthesis pathway (for pathway, click here).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 88201-43-8


1. Usui, S. and Yu, C.-A. Purification and properties of isopenicillin-N epimerase from Streptomyces clavuligerus. Biochim. Biophys. Acta 999 (1989) 78-85. [PMID: 2804141]

2. Laiz, L., Liras, P., Castro, J.M. and Martín, J.F. Purification and characterization of the isopenicillin-N epimerase from Nocardia lactamdurans. J. Gen. Microbiol. 136 (1990) 663-671.

3. Cantwell, C., Beckmann, R., Whiteman, P., Queener, S.W. and Abraham, E.P. Isolation of deacetoxycephalosporin-c from fermentation broths of Penicillium chrysogenum transformants - construction of a new fungal biosynthetic-pathway. Proc. R. Soc. Lond. B Biol. Sci. 248 (1992) 283-289. [PMID: 1354366]

4. Yeh, W.K., Ghag, S.K. and Queener, S.W. Enzymes for epimerization of isopenicillin N, ring expansion of penicillin N, and 3'-hydroxylation of deacetoxycephalosporin C. Function, evolution, refolding, and enzyme engineering. Ann. N.Y. Acad. Sci. 672 (1992) 396-408.

[EC created 2002]

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