Lawrence Berkeley National Laboratory
Programmed DNA destruction by miniature CRISPR-Cas14 enzymes.
- Author(s): Harrington, Lucas B
- Burstein, David
- Chen, Janice S
- Paez-Espino, David
- Ma, Enbo
- Witte, Isaac P
- Cofsky, Joshua C
- Kyrpides, Nikos C
- Banfield, Jillian F
- Doudna, Jennifer A
- et al.
Published Web Locationhttps://doi.org/10.1126/science.aav4294
CRISPR-Cas systems provide microbes with adaptive immunity to infectious nucleic acids and are widely employed as genome editing tools. These tools use RNA-guided Cas proteins whose large size (950 to 1400 amino acids) has been considered essential to their specific DNA- or RNA-targeting activities. Here we present a set of CRISPR-Cas systems from uncultivated archaea that contain Cas14, a family of exceptionally compact RNA-guided nucleases (400 to 700 amino acids). Despite their small size, Cas14 proteins are capable of targeted single-stranded DNA (ssDNA) cleavage without restrictive sequence requirements. Moreover, target recognition by Cas14 triggers nonspecific cutting of ssDNA molecules, an activity that enables high-fidelity single-nucleotide polymorphism genotyping (Cas14-DETECTR). Metagenomic data show that multiple CRISPR-Cas14 systems evolved independently and suggest a potential evolutionary origin of single-effector CRISPR-based adaptive immunity.