site-specific endodeoxyribonuclease activity, specific for altered base
Definition
Target type: molecularfunction
Catalysis of the hydrolysis of ester linkages at specific sites within a deoxyribonucleic acid molecule by creating internal breaks. [GOC:jl]
Site-specific endodeoxyribonuclease activity, specific for altered base, refers to the enzymatic function of cleaving DNA at specific sites where the base sequence has been altered. This alteration can involve a variety of modifications, including:
* **Base modifications:** This includes methylation, deamination, oxidation, and other chemical modifications that change the structure of a base.
* **Base mismatches:** These are errors in DNA replication where the wrong base is incorporated opposite a template base.
* **DNA lesions:** These are damages to DNA bases caused by exposure to radiation, chemicals, or reactive oxygen species.
The enzymes that exhibit this activity are often called **restriction endonucleases** or **DNA glycosylases**. They recognize the altered base or mismatch within a specific DNA sequence and cleave the phosphodiester backbone of the DNA molecule, creating a double-strand break. This cleavage can be either **5'-3'** or **3'-5'**, depending on the specific enzyme.
The molecular mechanism of site-specific endodeoxyribonuclease activity, specific for altered base, involves several steps:
1. **Recognition of the altered base:** The enzyme binds to the DNA molecule and specifically recognizes the altered base or mismatch.
2. **Cleavage of the phosphodiester bond:** The enzyme cleaves the DNA backbone at a specific site near the altered base.
3. **Removal of the altered base (in some cases):** Some enzymes, like DNA glycosylases, remove the altered base in addition to cleaving the DNA.
This activity plays a crucial role in various cellular processes, including:
* **DNA repair:** The enzymes can repair damaged DNA by removing the altered base and replacing it with the correct one.
* **Immune defense:** Some restriction endonucleases are used by bacteria to defend against invading viruses.
* **Genetic engineering:** Restriction endonucleases are widely used in molecular biology for manipulating DNA.
In summary, site-specific endodeoxyribonuclease activity, specific for altered base, is a crucial enzymatic function that recognizes and cleaves DNA at specific sites where the base sequence has been altered. This activity plays a vital role in DNA repair, immune defense, and genetic engineering.'
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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 |