Target type: molecularfunction
Binding to double-stranded telomere-associated DNA. [GOC:jl, ISBN:0321000382]
Double-stranded telomeric DNA binding is a crucial molecular function that plays a vital role in maintaining the integrity and stability of chromosomes. Telomeres are specialized structures at the ends of chromosomes that protect them from degradation and fusion. They consist of repetitive DNA sequences, typically rich in guanine and thymine bases (G-rich repeats), and associated proteins.
Double-stranded telomeric DNA binding proteins, such as TRF1 and TRF2 in humans, recognize and bind to the double-stranded telomeric DNA. This binding is highly specific and involves interactions with the G-rich repeats through a variety of mechanisms, including:
* **Base stacking:** The proteins stack their aromatic amino acids (tryptophan, phenylalanine, tyrosine) against the guanine bases of the telomeric DNA. This stacking interaction stabilizes the protein-DNA complex and contributes to the specificity of the binding.
* **Hydrogen bonding:** The protein residues form hydrogen bonds with the DNA bases, further enhancing the stability of the interaction.
* **Electrostatic interactions:** The protein’s positively charged residues interact with the negatively charged phosphate backbone of the DNA.
The binding of these proteins to the telomeric DNA is crucial for various functions, including:
* **Protection of chromosome ends:** The binding of proteins to the telomeres prevents the ends of chromosomes from being recognized as double-stranded breaks, which can lead to DNA degradation and chromosome fusion.
* **Regulation of telomere length:** Telomeric DNA is shortened with each round of DNA replication, and these proteins play a role in controlling the rate of telomere shortening.
* **Formation of the telomeric loop (T-loop):** TRF2 promotes the formation of a T-loop, a protective structure that hides the 3' overhang of the telomere. This structure further contributes to the stability of the telomere and prevents degradation.
* **Recruitment of other proteins:** These proteins can act as platforms for recruiting other proteins involved in telomere maintenance, including those involved in DNA replication, repair, and recombination.
Overall, the double-stranded telomeric DNA binding function is essential for the proper maintenance and stability of chromosomes. It is a highly regulated process involving specific protein-DNA interactions that ensure the integrity of the genome and prevent genomic instability.'
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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) |
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 |