IUBMB Enzyme Nomenclature


Accepted name: DNA-(apurinic or apyrimidinic site) lyase

Reaction: The C-O-P bond 3' to the apurinic or apyrimidinic site in DNA is broken by a β-elimination reaction, leaving a 3'-terminal unsaturated sugar and a product with a terminal 5'-phosphate

Other name(s): AP lyase; AP endonuclease class I; endodeoxyribonuclease (apurinic or apyrimidinic); deoxyribonuclease (apurinic or apyrimidinic); E. coli endonuclease III; phage-T4 UV endonuclease; Micrococcus luteus UV endonuclease; AP site-DNA 5'-phosphomonoester-lyase; X-ray endonuclease III

Systematic name: DNA-(apurinic or apyrimidinic site) 5'-phosphomonoester-lyase

Comments: 'Nicking' of the phosphodiester bond is due to a lyase-type reaction, not hydrolysis. This group of enzymes was previously listed as endonucleases, under EC

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 61811-29-8


1. Bailly, V., Sente, B. and Verly, W.G. Bacteriophage-T4 and Micrococcus luteus UV endonucleases are not endonucleases but β-elimination and sometimes βδ-elimination catalysts. Biochem. J. 259 (1989) 751-759. [PMID: 2471512]

2. Bailly, V. and Verly, W.G. Escherichia coli endonuclease III is not an endonuclease but a β-elimination catalyst. Biochem. J. 242 (1987) 565-572. [PMID: 2439070]

3. Bailly, V. and Verly, W.G. AP endonucleases and AP lyases. Nucleic Acids Res. 17 (1989) 3617-3618. [PMID: 2471157]

4. Manoharan, M., Mazumder, A., Ransom, S.C., Gerlt, J.A. and Bolton, P.H. Mechanism of UV endonuclease-V cleavage of abasic sites in DNA determined by C-13 labeling. J. Am. Chem. Soc. 110 (1988) 2690-2691.

[EC created 1978 as EC, transferred 1992 to EC]

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