What is Deamination and Depurination?

What is Deamination and Depurination?

Deamination, in which adenine and/or cytosine nucleotides lose amine groups. Depurination, in which a purine (adenine or guanine) is released from DNA.

Does homologous recombination repair?

Homologous recombination (HR) is a DNA metabolic process found in all forms of life that provides high-fidelity, template-dependent repair or tolerance of complex DNA damages including DNA gaps, DNA double-stranded breaks (DSBs), and DNA interstrand crosslinks (ICLs).

What does depurination mean?

Depurination is a term usually applied to the loss of a purine (which is more common) or a pyrimidine, leading to an abasic site (also called an apurinic site for the same reason). Abasic sites are the most common modification in the genome in most organisms, including humans.

What is depurination simple?

Depurination is a chemical reaction of purine deoxyribonucleosides, deoxyadenosine and deoxyguanosine, and ribonucleosides, adenosine or guanosine, in which the β-N-glycosidic bond is hydrolytically cleaved releasing a nucleic base, adenine or guanine, respectively.

What triggers homologous recombination?

​Homologous Recombination = Homologous recombination is a type of genetic recombination that occurs during meiosis (the formation of egg and sperm cells). Paired chromosomes from the male and female parent align so that similar DNA sequences from the paired chromosomes cross over each other.

How do you fix depurination?

Depurination, which is by far the most frequent type of damage suffered by DNA, also leaves a deoxyribose sugar with a missing base. Depurinations are directly repaired beginning with AP endonuclease, following the bottom half of the pathway in Figure 5-50A.

Is depurination caused by UV radiation?

Environmental Stressors and Gene Responses While a cell is desiccated damage may be introduced into DNA through chemical modifications (alkylation or oxidation), crosslinking, base removal such as depurination (that leaves a deoxyribose residue in the DNA backbone), or by the effects of ionizing and UV radiation.