base-excision repair, AP site formation
Definition
Target type: biologicalprocess
The formation of an AP site, a deoxyribose sugar with a missing base, by DNA glycosylase which recognizes an altered base in DNA and catalyzes its hydrolytic removal. This sugar phosphate is the substrate recognized by the AP endonuclease, which cuts the DNA phosphodiester backbone at the 5' side of the altered site to leave a gap which is subsequently repaired. [ISBN:0815316194]
Base-excision repair (BER) is a major DNA repair pathway that removes damaged or modified bases from DNA. The process begins with the recognition of the damaged base by a DNA glycosylase, which cleaves the glycosidic bond between the damaged base and the deoxyribose sugar in the DNA backbone. This leaves an apurinic/apyrimidinic (AP) site, a gap in the DNA where the base is missing. AP sites are highly unstable and can lead to DNA strand breaks if not repaired. AP sites are recognized by AP endonucleases, which cleave the phosphodiester bond 5' to the AP site, leaving a 3'-hydroxyl group and a 5'-deoxyribose phosphate (dRP) group. The dRP group is then removed by a dRP lyase, creating a single-stranded DNA gap. This gap is filled by DNA polymerase and the newly synthesized DNA strand is ligated to the original strand by DNA ligase, restoring the intact DNA double helix.'
"
Proteins (3)
| Protein | Definition | Taxonomy |
|---|---|---|
| N-glycosylase/DNA lyase | An N-glycosylase/DNA lyase that is encoded in the genome of human. [PRO:DNx, UniProtKB:O15527] | Homo sapiens (human) |
| Endonuclease III-like protein 1 | An endonuclease III-like protein 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P78549] | Homo sapiens (human) |
| DNA repair protein complementing XP-G cells | A DNA excision repair protein ERCC-5 that is encoded in the genome of human. [PRO:DNx] | Homo sapiens (human) |
Compounds (7)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| hydralazine | hydralazine : The 1-hydrazino derivative of phthalazine; a direct-acting vasodilator that is used as an antihypertensive agent. Hydralazine: A direct-acting vasodilator that is used as an antihypertensive agent. | azaarene; hydrazines; ortho-fused heteroarene; phthalazines | antihypertensive agent; vasodilator agent |
| isocarboxazid | Isocarboxazid: An MAO inhibitor that is effective in the treatment of major depression, dysthymic disorder, and atypical depression. It also is useful in the treatment of panic disorder and the phobic disorders. (From AMA, Drug Evaluations Annual, 1994, p311) | benzenes | |
| isoniazid | Hydra: A genus of freshwater polyps in the family Hydridae, order Hydroida, class HYDROZOA. They are of special interest because of their complex organization and because their adult organization corresponds roughly to the gastrula of higher animals. hydrazide : Compounds derived from oxoacids RkE(=O)l(OH)m (l =/= 0) by replacing -OH by -NRNR2 (R groups are commonly H). (IUPAC). | carbohydrazide | antitubercular agent; drug allergen |
| nialamide | Nialamide: An MAO inhibitor that is used as an antidepressive agent. | organonitrogen compound; organooxygen compound | |
| hydralazine hydrochloride | hydralazine hydrochloride : The hydrochloride salt of hydralazine; a direct-acting vasodilator that is used as an antihypertensive agent. | hydrochloride | antihypertensive agent; vasodilator agent |
| 3-hydroxy-quinazoline-2,4-dione | 3-hydroxy-quinazoline-2,4-dione: structure in first source | ||
| 4-phenyl-4-oxo-2-hydroxybuten-2-oic acid | 2,4-dioxo-4-phenylbutanoic acid: structure in first source |