uracil DNA N-glycosylase activity
Definition
Target type: molecularfunction
Catalysis of the cleavage of the N-C1' glycosidic bond between the damaged DNA base and the deoxyribose sugar, releasing a free base and leaving an apyrimidinic (AP) site. Enzymes with this activity recognize and remove uracil bases in DNA that result from the deamination of cytosine or the misincorporation of dUTP opposite an adenine. [GOC:elh, GOC:pr, PMID:9224623]
Uracil DNA N-glycosylase (UNG) activity is a crucial DNA repair mechanism that specifically removes uracil from DNA. Uracil is a common base analog that can arise in DNA due to deamination of cytosine. If left unrepaired, uracil can mispair with adenine during DNA replication, leading to mutations. UNG accomplishes this repair by employing a two-step process:
1. **Base Excision:** UNG first binds to the uracil-containing DNA. It then catalyzes the cleavage of the N-glycosidic bond between uracil and the deoxyribose sugar in the DNA backbone. This releases uracil from the DNA, leaving an abasic site (a gap in the DNA strand).
2. **Abasic Site Removal:** The abasic site is then recognized and removed by other DNA repair enzymes, such as AP endonucleases. This creates a gap in the DNA that is filled in by DNA polymerase, using the undamaged strand as a template. Finally, DNA ligase seals the nick, restoring the original DNA sequence.
The molecular function of UNG is essential for maintaining the integrity of the genome by eliminating potentially mutagenic uracil residues from DNA. This activity is crucial for preventing various diseases, including cancer. Mutations in the UNG gene are linked to certain types of genetic instability and increased susceptibility to cancer.'
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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 |