class II DNA-(apurinic or apyrimidinic site) endonuclease activity
Definition
Target type: molecularfunction
Catalysis of the hydrolysis of ester linkages immediately 5' to an apurinic/apyrimidinic (AP; also called abasic) site within a deoxyribonucleic acid molecule by creating internal breaks, generating a single-strand break with 5'-deoxyribose phosphate and 3'-hydroxyl ends. [PMID:19401441]
Class II DNA-(apurinic or apyrimidinic site) endonucleases are a family of enzymes that play a crucial role in DNA repair pathways. They specifically recognize and cleave DNA at abasic sites, also known as AP sites, which are lesions in the DNA backbone where a purine or pyrimidine base has been lost. These sites can arise from spontaneous hydrolytic DNA damage or from the action of other DNA repair enzymes. The enzymatic activity of class II DNA-(apurinic or apyrimidinic site) endonucleases is critical for removing these lesions and preventing the accumulation of DNA damage, which can lead to mutations, cell death, and cancer.
The mechanism of action of class II DNA-(apurinic or apyrimidinic site) endonucleases involves the recognition and binding to the abasic site in the DNA. This recognition is often facilitated by a conserved active site motif known as the "helix-hairpin-helix" motif. Once bound, the enzyme catalyzes the hydrolysis of the phosphodiester bond 5' to the abasic site, resulting in a single-stranded break in the DNA. This nick in the DNA allows other repair enzymes to access the damaged region and initiate the repair process.
Class II DNA-(apurinic or apyrimidinic site) endonucleases are found in all living organisms, from bacteria to humans, highlighting their essential role in maintaining genome integrity. They are involved in various DNA repair pathways, including base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR). Dysregulation of class II DNA-(apurinic or apyrimidinic site) endonuclease activity has been linked to various diseases, including cancer and neurodegenerative disorders.'
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Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| DNA-(apurinic or apyrimidinic site) endonuclease | A DNA-(apurinic or apyrimidinic site) endonuclease that is encoded in the genome of human. [PRO:DNx, UniProtKB:P27695] | Homo sapiens (human) |
Compounds (17)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| aurintricarboxylic acid | aurintricarboxylic acid : A member of the class of quinomethanes that is 3-methylidene-6-oxocyclohexa-1,4-diene-1-carboxylic acid in which the methylidene hydrogens are replaced by 4-carboxy-3-hydroxyphenyl groups. The trisodium salt is the biological stain 'chrome violet CG' while the triammonium salt is 'aluminon'. Aurintricarboxylic Acid: A dye which inhibits protein biosynthesis at the initial stages. The ammonium salt (aluminon) is a reagent for the colorimetric estimation of aluminum in water, foods, and tissues. | monohydroxybenzoic acid; quinomethanes; tricarboxylic acid | fluorochrome; histological dye; insulin-like growth factor receptor 1 antagonist |
| hycanthone | hycanthone : A thioxanthen-9-one compound having a hydroxymethyl substituent at the 1-position and a 2-[(diethylamino)ethyl]amino substituent at the 4-position. It was formerly used (particularly as the monomethanesulfonic acid salt) as a schistosomicide for individual or mass treatement of infection with Schistosoma haematobium and S. mansoni, but due to its toxicity and concern about possible carcinogenicity, it has been replaced by other drugs such as praziquantel. Hycanthone: Potentially toxic, but effective antischistosomal agent, it is a metabolite of LUCANTHONE. | thioxanthenes | mutagen; schistosomicide drug |
| lucanthone | lucanthone : A thioxanthen-9-one compound having a methyl substituent at the 1-position and a 2-[(diethylamino)ethyl]amino substituent at the 4-position. Formerly used for the treatment of schistosomiasis. It is a prodrug, being metabolised to hycanthone. Lucanthone: One of the SCHISTOSOMICIDES, it has been replaced largely by HYCANTHONE and more recently PRAZIQUANTEL. (From Martindale The Extrapharmacopoeia, 30th ed., p46) | thioxanthenes | adjuvant; antineoplastic agent; EC 5.99.1.2 (DNA topoisomerase) inhibitor; EC 5.99.1.3 [DNA topoisomerase (ATP-hydrolysing)] inhibitor; mutagen; photosensitizing agent; prodrug; schistosomicide drug |
| mitoxantrone hydrochloride | hydrochloride | antineoplastic agent | |
| 7-nitro-1h-indole-2-carboxylic acid | 7-nitro-1H-indole-2-carboxylic acid: acts on AP endonuclease, 3'-phosphodiesterase, and 3'-phosphatase activities of APE1; structure in first source | ||
| 3,3',4,4',5,5'-hexabromobiphenyl | |||
| 6-hydroxydopa | 6-hydroxydopa: RN given refers to cpd without isomeric designation | non-proteinogenic alpha-amino acid | |
| tanshinone ii a | tashinone IIA: a cardiovascular agent with antineoplastic activity; isolated from Salvia miltiorrhiza; structure in first source | abietane diterpenoid | |
| 1,3,6-trimethylpyrimido[5,4-e][1,2,4]triazine-5,7-dione | pyrimidotriazine | ||
| 2-[[5-(dimethylsulfamoyl)-1H-indol-3-yl]methylidene]propanedioic acid diethyl ester | indoles | ||
| 1,6-dimethyl-3-propylpyrimido[5,4-e][1,2,4]triazine-5,7-dione | pyrimidotriazine | ||
| myricetin | 7-hydroxyflavonol; hexahydroxyflavone | antineoplastic agent; antioxidant; cyclooxygenase 1 inhibitor; food component; geroprotector; hypoglycemic agent; plant metabolite | |
| ag 538 | AG 538: an IGF-1 receptor kinase inhibitor; structure in first source | ||
| e 3330 | E 3330: structure given in first source; MW 378.47 | ||
| N-[3-(1,3-benzothiazol-2-yl)-5,6-dihydro-4H-thieno[2,3-c]pyrrol-2-yl]acetamide | benzothiazoles | ||
| thiolactomycin | thiolactomycin: from actinomycetes; structure given in first source | ||
| galloflavin | galloflavin: structure in first source |