Prime editing, a new DNA editing tool, can mend most mutations that cause human disease

1

The prime editor contains an engineered protein that guides it to its target. On arrival, the editor uses an enzyme called cas9 to nick one strand of the DNA

Guide molecule

Cas9

Target DNA

2

The prime editor then churns out fresh DNA to be inserted at the site

Original DNA

strand removed

Fresh DNA inserted

3

Another guide protein then directs the prime editor to nick the unedited DNA strand

Unedited DNA strand is nicked

4

The cell repairs the nick by copying the edited strand, completing the edit

Fully edited DNA

1

2

The prime editor contains an engineered protein that guides it to its target. On arrival, the editor uses an enzyme called cas9 to nick one strand of the DNA

The prime editor then churns out fresh DNA to be inserted at the site

Original DNA

strand removed

Guide molecule

Cas9

Target DNA

Fresh DNA inserted

3

4

Another guide protein then directs the prime editor to nick the unedited DNA strand

The cell repairs the nick by copying the edited strand, completing the edit

Unedited DNA strand is nicked

Fully edited DNA