EC - Isopenicillin-N epimerase

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IntEnz Enzyme Nomenclature


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




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.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0045439
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 : 78-85 (1989). [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 : 663-671 (1990).
  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 : 283-289 (1992). [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 : 396-408 (1992).

[EC created 2002]