Page last updated: 2024-10-24
replication fork reversal
Definition
Target type: biologicalprocess
Replication fork processing that involves the unwinding of blocked forks to form four-stranded structures resembling Holliday junctions, which are subsequently resolved. [PMID:19406929]
Replication fork reversal is a crucial DNA repair mechanism that protects the genome from the detrimental effects of stalled or broken replication forks. These forks, which are the sites of DNA synthesis, can be stalled by various obstacles like DNA damage, tight protein-DNA complexes, or even the presence of DNA structures like G-quadruplexes. When a fork stalls, the replication machinery can be destabilized and exposed single-stranded DNA becomes vulnerable to damage. To circumvent this, cells have evolved replication fork reversal as a strategy to re-establish the stalled replication fork.
The process begins with the action of a specialized helicase, known as the RecQ helicase family. These helicases unwind the DNA duplex ahead of the stalled fork, essentially rewinding the DNA and creating a so-called "chicken-foot" structure. This structure involves two double-stranded DNA segments flanking a single-stranded region.
Next, the single-stranded DNA is resected, which means it is trimmed back by enzymes called nucleases. This creates a 3' single-stranded tail that serves as a substrate for the action of a polymerase, which can then synthesize DNA using the complementary strand as a template. This DNA synthesis fills in the gap created by the resection and allows the stalled fork to be re-established.
Crucially, this process involves the formation of a Holliday junction. This is a branched DNA structure that occurs when two DNA strands exchange partners. This junction is resolved through a specific set of enzymatic steps. These steps involve a specialized enzyme called a Holliday junction resolvase, which cleaves the junction and allows the re-established replication fork to continue its journey down the DNA molecule.
Overall, replication fork reversal is a dynamic and complex process that involves multiple enzymatic steps, including helicase activity, nucleolytic resection, DNA synthesis, and Holliday junction resolution. It plays a critical role in protecting the genome from damage and ensuring the faithful replication of DNA. This process is essential for maintaining genomic integrity and preserving the stability of the cell.'
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Proteins (3)
| Protein | Definition | Taxonomy |
|---|---|---|
| Poly [ADP-ribose] polymerase 1 | A poly [ADP-ribose] polymerase 1 that is encoded in the genome of cow. [OMA:P18493, PRO:DNx] | Bos taurus (cattle) |
| Histone-arginine methyltransferase CARM1 | A histone-arginine methyltransferase CARM1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q86X55] | Homo sapiens (human) |
| Poly [ADP-ribose] polymerase 1 | A poly [ADP-ribose] polymerase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P09874] | Homo sapiens (human) |
Compounds (57)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| niacinamide | nicotinamide : A pyridinecarboxamide that is pyridine in which the hydrogen at position 3 is replaced by a carboxamide group. | pyridine alkaloid; pyridinecarboxamide; vitamin B3 | anti-inflammatory agent; antioxidant; cofactor; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; EC 3.5.1.98 (histone deacetylase) inhibitor; Escherichia coli metabolite; geroprotector; human urinary metabolite; metabolite; mouse metabolite; neuroprotective agent; Saccharomyces cerevisiae metabolite; Sir2 inhibitor |
| 1,5-dihydroxyisoquinoline | 1,5-dihydroxyisoquinoline: structure in first source isoquinoline-1,5-diol : An isoquinolinol that is isoquinoline in which the hydrogens at positions 1 and 5 are replaced by hydroxy groups. | isoquinolinol | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor |
| 3-aminobenzamide | benzamides; substituted aniline | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor | |
| 4-amino-1,8-naphthalimide | 4-amino-1,8-naphthalimide: inhibits ADP-ribosylation; sometimes abreviated as 4-AN; | benzoisoquinoline; dicarboximide | |
| phenanthridone | phenanthridone : A member of the class of phenanthridines that is phenanthridine with an oxo substituent at position 6. A poly(ADP-ribose) polymerase (PARP) inhibitor, it has been shown to exhibit immunosuppressive activity. phenanthridone: coal tar derivative; structure given in first source | lactam; phenanthridines | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; immunosuppressive agent; mutagen |
| 5-aminoisoquinolinone | 5-aminoisoquinolinone: structure in first source | isoquinolines | |
| benzamide | benzamide : An aromatic amide that consists of benzene bearing a single carboxamido substituent. The parent of the class of benzamides. | benzamides | |
| pj-34 | PJ34 : A member of the class of phenanthridines that is 5,6-dihydrophenanthridine substituted at positions 2 and 6 by (N,N-dimethylglycyl)amino and oxo groups, respectively. It is a potent inhibitor of poly(ADP-ribose) polymerases PARP1 and PARP2 (IC50 of 110 nM and 86 nM, respectively) and exhibits anti-cancer, cardioprotective and neuroprotective properties. | phenanthridines; secondary carboxamide; tertiary amino compound | angiogenesis inhibitor; anti-inflammatory agent; antiatherosclerotic agent; antineoplastic agent; apoptosis inducer; cardioprotective agent; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; neuroprotective agent |
| 1-hydroxyphthalazine | 1-hydroxyphthalazine: RN given refers to cpd with unspecified locants; do not confuse with cpd phthalazinol RN: 56611-65-5 | phthalazines | |
| chlorthenoxazin | chlorthenoxazin: RN given refers to parent cpd; structure | benzoxazine | |
| isocarbostyril | isoquinolinone : An isoquinoline containing one or more oxo groups. | isoquinolines | |
| flavone | flavone : The simplest member of the class of flavones that consists of 4H-chromen-4-one bearing a phenyl substituent at position 2. flavone: RN given refers to unlabeled cpd; structure given in first source | flavones | metabolite; nematicide |
| 2,4(1h,3h)-quinazolinedione | 2,4(1H,3H)-quinazolinedione: structure given in first source | ||
| 4-hydroxybenzamide | |||
| naphthalimides | Naphthalimides: Compounds with three fused rings that appear like a naphthalene fused to piperidone or like a benz(de)isoquinoline-1,3-dione (not to be confused with BENZYLISOQUINOLINES which have a methyl separating the naphthyl from the benzyl rings). Members are CYTOTOXINS. | ||
| 4-fluorobenzamide | 4-fluorobenzamide: structure in first source | ||
| 5-iodo-6-amino-1,2-benzopyrone | |||
| alantolactone | alantolactone : A sesquiterpene lactone that is 3a,5,6,7,8,8a,9,9a-octahydronaphtho[2,3-b]furan-2-one bearing two methyl substituents at positions 5 and 8a as well as a methylidene substituent at position 3. alantolactone: allergenic sesquiterpene lactone; crystalline mixture of alantolactones from group of sesquiterpenes; structure | naphthofuran; olefinic compound; sesquiterpene lactone | antineoplastic agent; apoptosis inducer; plant metabolite |
| 4-aminobenzamide | benzamides | ||
| 4-Methoxybenzamide | benzamides | ||
| 3-methoxybenzamide | |||
| furamidine | furamidine: RN given refers to parent cpd; WR 199385 refers to di-HCl; pafuramidine is a prodrug of this | ||
| 3',4'-dihydroxyflavone | 3',4'-dihydroxyflavone: inhibitors of arachidonic acid peroxidation | ||
| 3,4-dihydro-5-methyl-1(2h)-isoquinolinone | 3,4-dihydro-5-methyl-1(2H)-isoquinolinone: structure given in first source | isoquinolines | |
| 1-oxo-1,2,3,4-tetrahydroisoquinoline | 1-oxo-1,2,3,4-tetrahydroisoquinoline: structure given in first source | ||
| cyclo(alanylalanyl) | |||
| s-adenosylhomocysteine | S-adenosyl-L-homocysteine : An organic sulfide that is the S-adenosyl derivative of L-homocysteine. S-Adenosylhomocysteine: 5'-S-(3-Amino-3-carboxypropyl)-5'-thioadenosine. Formed from S-adenosylmethionine after transmethylation reactions. | adenosines; amino acid zwitterion; homocysteine derivative; homocysteines; organic sulfide | cofactor; EC 2.1.1.72 [site-specific DNA-methyltransferase (adenine-specific)] inhibitor; EC 2.1.1.79 (cyclopropane-fatty-acyl-phospholipid synthase) inhibitor; epitope; fundamental metabolite |
| N-[4-[[[4-(4-methoxyphenyl)-4-oxanyl]methylamino]-oxomethyl]phenyl]-2-furancarboxamide | aromatic amide; furans | ||
| ha 1100 | HA 1100: intracellular calcium antagonist | ||
| apigenin | Chamomile: Common name for several daisy-like plants (MATRICARIA; TRIPLEUROSPERMUM; ANTHEMIS; CHAMAEMELUM) native to Europe and Western Asia, now naturalized in the United States and Australia. | trihydroxyflavone | antineoplastic agent; metabolite |
| luteolin | 3'-hydroxyflavonoid; tetrahydroxyflavone | angiogenesis inhibitor; anti-inflammatory agent; antineoplastic agent; apoptosis inducer; c-Jun N-terminal kinase inhibitor; EC 2.3.1.85 (fatty acid synthase) inhibitor; immunomodulator; nephroprotective agent; plant metabolite; radical scavenger; vascular endothelial growth factor receptor antagonist | |
| amentoflavone | biflavonoid; hydroxyflavone; ring assembly | angiogenesis inhibitor; antiviral agent; cathepsin B inhibitor; P450 inhibitor; plant metabolite | |
| 3',4',7-trihydroxyflavone | 3',4',7-trihydroxyflavone: from the Sudanese medicinal plant Albizia zygia; structure in first source | flavones | |
| stilbamidine | stilbamidine: RN given refers to parent cpd | ||
| adenosine diphosphate (hydroxymethyl)pyrrolidinediol | dihydroxypyrrolidine; purine ribonucleoside 5'-diphosphate | ||
| ag 14361 | benzimidazoles | ||
| gpi 6150 | |||
| rucaparib | AG14447: Poly(ADP-ribose) polymerase inhibitor; structure in first source | azepinoindole; caprolactams; organofluorine compound; secondary amino compound | antineoplastic agent; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor |
| 3,4-dihydro-5-(4-(1-piperidinyl)butoxy)-1(2h)-isoquinolinone | |||
| veliparib | benzimidazoles | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor | |
| olaparib | cyclopropanes; monofluorobenzenes; N-acylpiperazine; phthalazines | antineoplastic agent; apoptosis inducer; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor | |
| niraparib | 2-[4-(piperidin-3-yl)phenyl]-2H-indazole-7-carboxamide : A member of the class of indazoles that is 2H-indazole substituted by 4-(piperidin-3-yl)phenyl and aminocarbonyl groups at positions 2 and 7, respectively. It is a potent PARP1 inhibitor with IC50 of 3.2 nM. | benzenes; indazoles; piperidines; primary carboxamide | antineoplastic agent; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor |
| niraparib | niraparib : A 2-[4-(piperidin-3-yl)phenyl]-2H-indazole-7-carboxamide that has S-configuration. It is a potent inhibitor of PARP1 and PARP2 (IC50 of 3.8 and 2.1 nM, respectively) and approved as a first-line maintenance treatment for women with advanced ovarian cancer after responding to platinum-based chemotherapy. niraparib: structure in first source | 2-[4-(piperidin-3-yl)phenyl]-2H-indazole-7-carboxamide | antineoplastic agent; apoptosis inducer; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; radiosensitizing agent |
| cep 26401 | pyridazines; ring assembly | ||
| iwr-1 endo | IWR-1-endo : A dicarboximide having an endo bridged phthalimide structure, substituted at nitrogen by a 4-(quinolin-8-ylcarbamoyl)benzoyl group. | benzamides; bridged compound; dicarboximide; quinolines | axin stabilizer; Wnt signalling inhibitor |
| nms-p118 | NMS-P118: a PARP-1 inhibitor; structure in first source | ||
| g007-lk | G007-LK: potent and specific small-molecule tankyrase inhibitor; structure in first source | ||
| gsk343 | GSK343 : A member of the class of indazoles that is 1-isopropyl-1H-indazole-4-carboxamide in which the nitrogen of the carboxamide group is substituted by a (6-methyl-2-oxo-4-propyl-1,2-dihydropyridin-3-yl)methyl group and in which the indazole ring is substituted at position 6 by a 2-(4-methylpiperazin-1-yl)pyridin-4-yl group. A highly potent and selective EZH2 inhibitor (IC50 = 4 nM). GSK343: an EZH2 methyltransferase inhibitor | aminopyridine; indazoles; N-alkylpiperazine; N-arylpiperazine; pyridone; secondary carboxamide | antineoplastic agent; apoptosis inducer; EC 2.1.1.43 (enhancer of zeste homolog 2) inhibitor |
| nu 1025 | NU 1064: structure in first source | phenols; quinazolines | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor |
| 2-methyl-4(3h)-quinazolinone | 2-methyl-4(3H)-quinazolinone: from Bacillus cereus; structure given in first source | ||
| 4-hydroxyquinazoline | 4-oxo-3,4-dihydroquinazoline: structure in first source | quinazolines | |
| 1,4-Dihydrothieno[3,2-d]pyrimidin-4-one | organic heterobicyclic compound; organonitrogen heterocyclic compound; organosulfur heterocyclic compound | ||
| xav939 | XAV939 : A thiopyranopyrimidine in which a 7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine skeleton is substituted at C-4 by a hydroxy group and at C-2 by a para-(trifluoromethyl)phenyl group. XAV939: selectively inhibits beta-catenin-mediated transcription; structure in first source | (trifluoromethyl)benzenes; thiopyranopyrimidine | tankyrase inhibitor |
| 2-(4-methoxyphenyl)-1H-quinazolin-4-one | quinazolines | ||
| bmn 673 | talazoparib: inhibits both PARP1 and PARP2; structure in first source | ||
| me0328 | ME0328: inhibits ARTD3; structure in first source | ||
| nvp-tnks656 |