What is hydrolytic damage?
Hydrolytic DNA damage involves deamination or the total removal of individual bases. Loss of DNA bases, known as AP (apurinic/apyrimidinic) sites, can be particularly mutagenic and if left unrepaired they can inhibit transcription.
What is hydrolysis of DNA?
Hydrolysis of the DNA backbone is an important reaction in biology and in the laboratory manipulation of genetic material. While many enzymes catalyze the sequence-selective hydrolysis of DNA, it has been difficult to design nonprotein catalysts for this purpose.
What does the hydrolysis of DNA result in?
Complete hydrolysis of chromosomal nucleic acids gave inorganic phosphate, 2-deoxyribose (a previously unknown sugar) and four different heterocyclic bases (shown in the following diagram). To reflect the unusual sugar component, chromosomal nucleic acids are called deoxyribonucleic acids, abbreviated DNA.
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.
What causes gene damage?
DNA can be damaged via environmental factors as well. Environmental agents such as UV light, ionizing radiation, and genotoxic chemicals. Replication forks can be stalled due to damaged DNA and double strand breaks are also a form of DNA damage.
What is genes mutation?
A gene mutation (myoo-TAY-shun) is a change in one or more genes. Some mutations can lead to genetic disorders or illnesses.
Can RNA be broken down by hydrolysis?
RNA hydrolysis is a reaction in which a phosphodiester bond in the sugar-phosphate backbone of RNA is broken, cleaving the RNA molecule. RNA is susceptible to this base-catalyzed hydrolysis because the ribose sugar in RNA has a hydroxyl group at the 2′ position.
What are examples of hydrolysis?
Dissolving a salt of a weak acid or base in water is an example of a hydrolysis reaction. Strong acids may also be hydrolyzed. For example, dissolving sulfuric acid in water yields hydronium and bisulfate.
How does the structure of DNA change if hydrogen bonds are broken?
DNA replication occurs through the help of several enzymes. These enzymes “unzip” DNA molecules by breaking the hydrogen bonds that hold the two strands together. Each strand then serves as a template for a new complementary strand to be created.
What can depurination lead to?
Depurinated bases in single-stranded DNA undergoing replication can lead to mutations, because in the absence of information from the complementary strand, BER can add an incorrect base at the apurinic site, resulting in either a transition or transversion mutation.
What is hydrolytic DNA damage?
Hydrolytic DNA damage involves deamination or the total removal of individual bases. Loss of DNA bases, known as AP (apurinic / apyrimidinic) sites, can be particularly mutagenic and if left unrepaired they can inhibit transcription.
How do polycyclic aromatic hydrocarbons damage DNA?
DNA damage may also result from exposure to polycyclic aromatic hydrocarbons ( PAHs ). PAHs are potent, ubiquitous atmospheric pollutants commonly associated with oil, coal, cigarette smoke, and automobile exhaust fumes. A common marker for DNA damage due to PAHs is Benzo (a) pyrene diol epoxide ( BPDE ).
What happens when N-glycosyl bonds are hydrolyzed?
This is in contrast with RNA in which the phosphodiester bond in the backbone is the least stable under the same conditions. Hydrolysis of the N-glycosyl bond results in the loss of a base leaving an apurinic/apyrimidinic (AP) site that itself eventually decomposes into a nick.
What is the half life of hydrolytic ring opening in DNA?
The half-life of this process is 3.5 h for the FAPy derivative of deoxyguanosine in a nucleoside derivative (123, 126) and 16 h for the FAPy derivative of aflatoxin B1 in a single-stranded DNA oligomer (124). Open in a separate window Scheme 7 Adenine residues alkylated at the N1-position are also prone to hydrolytic ring opening.