A guy came up to me at a party last weekend, and asked, “Hey, do you know about CRISPRs?” and I thought, “Sure, I know how to keep my vegetables fresh in the fridge.” But, as my new friend explained, CRISPR is an acronym for: Clustered Regularly Interspaced Short Palindromic Repeats, which is an excellent excuse for an acronym.
The CRISPR Cas9 system is used to target and edit specific areas of the genome. The way it works is that a short piece of RNA which matches the section or DNA we want to target is attached to an endonuclease (Cas9). The endonuclease can then locate the matching bit of DNA and then cut both strands of the DNA at that point. This can either disrupt the gene, turning it off, or allow entirely new sequences to be appended to the genome.
This render is based on the crystal structure of Cas9 in Complex with Guide RNA and Target DNA (pdb 4oo8) in the protein data bank. The gold protein is the Cas9 endonuclease, the guide RNA is green, and the DNA is purple. The pdb data only includes the targeted portion of the DNA, so I added the leading and trailing portion DNA strand, and the loose unbound half is my best guess as to where it goes while the target DNA is bound to the guide RNA. I’m interested in doing more images or animations of this process, so if you can see something I’m doing wrong, please let me know in the comments.