TALeffektornukleaser

TALeffektornukleaser, often abbreviated as TALENs, are a class of engineered DNA-binding proteins that can be used to cut DNA at specific locations. They are derived from TAL effectors, which are proteins secreted by the bacterium Xanthomonas. These naturally occurring TAL effectors are used by the bacteria to manipulate plant genes during infection.

The key feature of TALENs is their modular DNA-binding domain. This domain is composed of repeating units, each of which recognizes a single DNA base. By assembling a specific sequence of these repeating units, scientists can create a TALEN that will bind to virtually any desired DNA sequence. Attached to this DNA-binding domain is a nuclease domain, typically FokI. When two TALENs bind to adjacent sites on the DNA, their FokI domains dimerize and cut the DNA, creating a double-strand break.

This ability to precisely cut DNA at a targeted location is what makes TALENs so valuable in biotechnology and genetic research. Once the DNA is cut, the cell's natural repair mechanisms are activated. Scientists can exploit these repair pathways to introduce specific genetic modifications. For example, the break can be repaired by non-homologous end joining, which often results in small insertions or deletions that can disrupt a gene. Alternatively, if a DNA template is provided, the break can be repaired by homology-directed repair, allowing for the precise insertion or replacement of DNA sequences.

TALENs have been instrumental in the development of gene editing technologies and have applications in areas such as basic biological research, drug discovery, and the development of gene therapies. They offer a way to engineer the genomes of a wide variety of organisms with unprecedented precision.