double-stranded DNA 3'-5' DNA exonuclease activity
Definition
Target type: molecularfunction
Catalysis of the sequential cleavage of mononucleotides from a free 3' terminus of a double-stranded DNA molecule. [GOC:mah, PMID:22562358]
Double-stranded DNA 3'-5' exonuclease activity refers to the enzymatic ability to degrade double-stranded DNA by removing nucleotides from the 3' end of the molecule. This activity is crucial for a variety of cellular processes, including DNA replication, repair, and recombination.
Here is a detailed description of the molecular function of this activity:
* **Mechanism:** The exonuclease enzyme binds to the double-stranded DNA molecule and uses its active site to hydrolyze the phosphodiester bond between the 3'-hydroxyl group of the terminal nucleotide and the phosphate group of the penultimate nucleotide. This results in the release of a single nucleotide from the 3' end of the DNA molecule. The enzyme then moves one nucleotide position towards the 5' end and repeats the process, progressively degrading the DNA strand.
* **Specificity:** The exonuclease typically exhibits a strong preference for double-stranded DNA substrates. Some exonucleases can also exhibit limited activity on single-stranded DNA, but their primary function is on double-stranded DNA.
* **Directionality:** The exonuclease activity is 3'-5', meaning it proceeds from the 3' end towards the 5' end of the DNA molecule.
* **Biological Significance:**
* **DNA Replication:** During DNA replication, exonucleases are essential for removing incorrect nucleotides that may be incorporated by DNA polymerase. This proofreading function ensures the fidelity of DNA replication.
* **DNA Repair:** Exonucleases play a critical role in DNA repair pathways. They can remove damaged nucleotides from the DNA strand to facilitate repair by other enzymes.
* **DNA Recombination:** Exonucleases contribute to homologous recombination by processing the ends of DNA molecules to generate single-stranded DNA tails that are necessary for recombination.
* **Regulation:** The activity of exonucleases is tightly regulated to ensure that they only act on specific DNA substrates at appropriate times. This regulation involves interactions with other proteins and modifications of the exonuclease itself.
Overall, the 3'-5' exonuclease activity is a fundamental enzymatic function that is vital for maintaining the integrity and stability of the genome.'
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Proteins (2)
| 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) |
| Cell cycle checkpoint protein RAD1 | A cell cycle checkpoint protein RAD1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O60671] | Homo sapiens (human) |
Compounds (18)
| 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 | ||
| 3-chloro-1-(3,4-dichlorophenyl)-4-(4-morpholinyl)-1h-pyrrole-2,5-dione | 3-chloro-1-(3,4-dichlorophenyl)-4-(4-morpholinyl)-1H-pyrrole-2,5-dione: an inhibitor of RAD51 that disrupts homologous recombination in human cells; structure in first source | ||
| 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 |