Peter Attia· MD
but Zin finger was a really challenging system for scientists to adapt and use because it required very sophisticated protein engineering U the way it works is that um zinc fingers are are protein domains they're just one glob of protein each finger each zinc finger can recogniz three letters of DNA and they occur in nature so you can find them in naturally occurring DNA binding proteins called transcription factors and they allow transcription factors to go and recognize different genes in the genome to modulate their activity either turn them on or turn them off or change how much they are expressing the cell but how do you get specificity when you are only recognizing three nucleotides the probability of three those three nucleotides showing up seems pretty likely across the genome right right exactly so so Nature has solved this problem by forming zinc finger arrays so they tether multiple fingers together and all of them have to hit their target of three nucle correct that's right so if you have an array of three fingers they recognize as nine letters if you have array of six fingers then that's 18 letters so in a complicated genome like our genome with three billion letters 18 would give us uniqueness so 18 can't allow you to find or Define just a single position and that's because four to the power of 18 is a big enough number it's bigger than 3 billion yeah