Zinc Finger Nuclease (ZFN), the first artificial restriction enzyme

Zinc finger nuclease (ZFN) is the first of the three artificial restriction enzymes developed in 1996, and the first to be used in genome editing in human cells in the mid-2000s. The DNA-binding part of ZFNs is composed of a series of 30 amino acids called "zinc fingers" and a cleavage enzyme called "Fokl".

A single zinc finger is capable of recognizing three bases. This makes it possible to recognize a specific base by changing the type of zinc finger. For example, by combining eight zinc fingers, 24 bases can be recognized. Since a particular sequence of 24 consecutive bases can theoretically appear in only one place in mammals, the target can be manipulated with certainty. Fokl has a property that prevents it from cutting DNA in the wrong place and only cuts when two are aligned on either side of the DNA to cut the desired location.

Second generation "TALEN"

TALEN was developed based on the discovery of a plant pathogen, which has a protein called "TAL REPEAT", in which 34 amino acid sequences appear repeatedly. The critical difference between TALEN and ZFN is the one-to-one correspondence between TAL REPEAT and bases.

Genome editing is done by using "artificial restriction enzymes" such as "ZFN" and "TALEN" to find the target base sequence in DNA and cut the DNA.

	Is this the end of genome editing technology?