IUBMB Enzyme Nomenclature


Accepted name: T4 deoxyribonuclease IV

Reaction: Endonucleolytic cleavage of the 5' phosphodiester bond of deoxycytidine in single-stranded DNA.

Other name(s): T4 endonuclease IV; EndoIV (ambiguous); denB (gene name)

Comments: This phage T4 enzyme is involved in degradation of host DNA. The enzyme does not cleave double-stranded DNA or native T4 DNA, which contains 5-hydroxymethylcytosine instead of cytosine.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Sadowski, P.D. and Hurwitz, J. Enzymatic breakage of deoxyribonucleic acid. II. Purification and properties of endonuclease IV from T4 phage-infected Escherichia coli. J. Biol. Chem. 244 (1969) 6192-6198. [PMID: 4900512]

2. Ling, V. Partial digestion of 32P-fd DNA with T4 endonuclease IV. FEBS Lett 19 (1971) 50-54. [PMID: 11946172]

3. Sadowski, P.D. and Bakyta, I. T4 endonuclease IV. Improved purification procedure and resolution from T4 endonuclease 3. J. Biol. Chem. 247 (1972) 405-412. [PMID: 4550601]

4. Bernardi, A., Maat, J., de Waard, A. and Bernardi, G. Preparation and specificity of endonuclease IV induced by bacteriophage T4. Eur. J. Biochem. 66 (1976) 175-179. [PMID: 782881]

5. Hirano, N., Ohshima, H. and Takahashi, H. Biochemical analysis of the substrate specificity and sequence preference of endonuclease IV from bacteriophage T4, a dC-specific endonuclease implicated in restriction of dC-substituted T4 DNA synthesis. Nucleic Acids Res. 34 (2006) 4743-4751. [PMID: 16971463]

6. Ohshima, H., Hirano, N. and Takahashi, H. A hexanucleotide sequence (dC1-dC6 tract) restricts the dC-specific cleavage of single-stranded DNA by endonuclease IV of bacteriophage T4. Nucleic Acids Res. 35 (2007) 6681-6689. [PMID: 17940096]

[EC created 2014]

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