The Super Protein That Can Cut DNA and Revolutionize Genetic Engineering

We may earn a commission from links on this page.

When scientists Phillipe Horvath and Rodolphe Barrangou set out to find a better way to make yogurt, they didn't expect to stumble across one of the future's most promising discoveries: a super protein that can accurately cut DNA—and could perhaps revolutionize genetic engineering.

The protein, called Cas9, can be exploited to snip strands of DNA in exactly the place researchers want. It doesn't make genetic engineering easy, but does make it much, much easier—as it allows researchers to splice sequences of DNA together affordably, with unprecedented accuracy.

So how does it work? Well, Cas9 was found last year to join forces with bacteria in such a way that, combined, they home into viruses and kill them by cutting their DNA at specific, targeted points. That's interesting—in fact, it made it a prime candidate for making yogurt production more efficient.


But what's more interesting is that Cas9 can be paired with any string of RNA—strings of molecules not unlike DNA which code and regulate gene expression—to target a matching piece of DNA and snip it with incredible accuracy. Kind of like a pair of tiny, custom DNA scissors. That's not interesting—that's amazing.

Now, though, reports Forbes, the world of biology is swarming over Cas9 and the possibilities it affords. George Church of Harvard University explains:

"It is spreading like wildfire from everyone who knows about it and it certainly is very tantalizing. It's easy to get in and start doing lots of experiments."

The embrace of Cas9 could bring with it massive advances, then. Not least the ability to study genetics in ways never before possible. Forbes explains:

[S]ay there are three changes in the DNA in or around a gene that might cause a disease. Right now, it's hard to study them directly. But now, Church says, you could take a cell from a person who has already had their DNA sequenced, as he is doing with his Personal Genome Project. Then you'd create what's known as an induced pluripotent stem cell, a cell that behaves much like one in an embryo. After that, you could use Cas9 to change each of those DNA spelling changes.


There is, of course, still a long way to go—this research is being conducted in Petri dishes right now, not living creatures—but it's a long time since a single protein had the entire world of biology so excited. It's only a matter of time before something major comes of it; not bad, for a protein which was originally discovered to make better yogurt. [Forbes, Science]