Nuclease Excision
Nuclease Excision - Related Videos
12:04
Mouse Genome Engineering Using Designer Nucleases
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Cited by 14 •
2014
Designer nucleases such as zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) can be used to modify the genome of mouse preimplantation embryos by triggering both the nonhomologous end joining (NHEJ) and homologous recombination (HR) pathways. These advances enable the rapid generation of mice with precise genetic modifications.
01:54
Base Excision Repair
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2020
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template. The first step of...
08:13
Overexpressing and Purifying a Toxic Nuclease from Escherichia coli
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2025
This article describes a methodology for overexpressing recombinant Nsp15, a toxic nuclease, in a C41(DE3) expression system, followed by purification of the tagged protein utilizing affinity and size exclusion chromatography. These protocols can be adapted for other challenging toxic proteins.
07:50
Detection and Removal of Nuclease Contamination During Purification of Recombinant Prototype Foamy Virus Integrase
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Cited by 10 •
2017
Recombinant prototype foamy virus integrase protein is often contaminated with a bacterial nuclease during purification. This method identifies nuclease contamination and removes it from the final preparation of the enzyme.
09:11
Genome Editing with CompoZr Custom Zinc Finger Nucleases (ZFNs)
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Cited by 28 •
2012
The CompoZr Custom Zinc-Finger Nuclease (ZFN) Service enables precise genome editing in any organism or cell line at any locus defined by the user. This article describes the process for the design, manufacture, validation and implementation of the CompoZr Custom ZFN Service.
FAQs
Recognition depends on whether a region contains a damaged, mismatched, or otherwise targeted sequence. In nucleotide excision repair, the important signal is distortion of the DNA helix rather than merely the presence of a particular base. This structural change directs repair proteins to the affected region, allowing cleavage to occur around the lesion instead of randomly along the strand.
Incisions on both sides isolate the damaged region as a removable oligonucleotide. This creates a defined gap in the affected DNA strand while leaving the surrounding sequence available as a template for restoration. DNA polymerase fills the gap, and DNA ligase seals the remaining break, completing repair and restoring strand continuity.
The target determines the biological context and the repair outcome. A damaged or helix-distorting DNA segment can be removed during nucleotide excision repair, whereas mismatched or otherwise selected nucleic acid regions may also be substrates for nuclease action. The shared principle is phosphodiester-bond cleavage, but the recognition process identifies the particular segment requiring removal.
A typical event begins when proteins recognize an abnormal or damaged region. Nucleases then cut the DNA strand on both sides of that region, allowing the intervening oligonucleotide to be removed. DNA polymerase replaces the missing sequence, and DNA ligase seals the repaired strand. Together, these steps convert lesion recognition into restoration of an intact DNA molecule.
Excision alone leaves a gap that must be repaired. DNA polymerase supplies the replacement step by filling the missing region, while DNA ligase closes the remaining break in the sugar-phosphate backbone. Their coordinated action is essential because removing the lesion without restoring continuity would not produce a functional, intact DNA strand.
By removing damaged or mismatched nucleic acid segments before they compromise genetic information, the process helps prevent mutations and supports accurate DNA replication and transcription. Its importance is also evident in disease biology: defects in genome-maintenance pathways can produce disorders associated with inadequate DNA repair, making excision mechanisms useful for studying cellular dysfunction.