What is the role of DNA glycosylases in base excision repair?
DNA glycosylases recognize and remove damaged bases from DNA by cleaving the base–sugar (N-glycosylic) bond, and downstream base excision repair enzymes restore the correct nucleotide.
Does base excision repair require DNA polymerase?
BER requires only four or five enzymes in the basic reaction steps to carry out repair of DNA containing AP sites or base damage. These include a DNA glycosylase, an AP endonuclease, a DNA polymerase, and a DNA ligase 15.
What is DNA damage and repair?
The pathway of cellular DNA damage and repair that leads to senescence, apoptosis, or cancer. To compensate for the degree and types of DNA damage that occur, cells have developed multiple repair processes including mismatch, base excision, and nucleotide excision repair mechanisms, with little process redundancy.
What are DNA repair pathways?
DNA repair pathways are triggered to maintain genetic stability and integrity when mammalian cells are exposed to endogenous or exogenous DNA-damaging agents. The deregulation of DNA repair pathways is associated with the initiation and progression of cancer.
What is direct DNA repair?
Introduction. Direct repair is defined as the elimination of DNA and RNA damage using chemical reversion that does not require a nucleotide template, breakage of the phosphodiester backbone or DNA synthesis.
What is base excision repair mechanism?
Base excision repair (BER) is a cellular mechanism, studied in the fields of biochemistry and genetics, that repairs damaged DNA throughout the cell cycle. It is responsible primarily for removing small, non-helix-distorting base lesions from the genome.
What is DNA glycosylase repair?
DNA glycosylase repair, also known as base excision repair (BER), is a mechanism present in all living cells, which removes lesions generated by spontaneous DNA decay, endogenous or exogenous genotoxic agents. If unrepaired, these base lesions induce mutations and cell death, and contribute to aging and cancer.
Why are glycosylases important to the function of DNA?
Given their ability to interrogate the surface of DNA bases by flipping them out of the helix into a selective active site pocket, DNA glycosylases represent efficient tools to specifically recognize unduly modified bases and eliminate them from the DNA, thereby enforcing genetic integrity.
How does the novel DNA glycosylase NEIL1 work?
The novel DNA glycosylase, NEIL1, protects mammalian cells from radiation-mediated cell death. DNA Repair (Amst) 2003;2:581–591. doi: 10.1016/S1568-7864(03)00025-9. [PubMed] [CrossRef] [Google Scholar] Rusmintratip V, Sowers LC. An unexpectedly high excision capacity for mispaired 5-hydroxymethyluracil in human cell extracts.
What is the function of base excision repair machinery?
The base excision repair machinery protects DNA in cells from the damaging effects of oxidation, alkylation, and deamination; it is specialized to fix single-base damage in the form of small chemical modifications.