Architecture of a DNA-guided Cas12a
CRISPR/Cas systems have largely been restricted to RNA-guided nucleases. Here, we present the cryo-EM structure of <i>Acidaminococcus</i> sp. Cas12a (AsCas12a) bound to a pseudo-DNA (ΨDNA) guide and RNA target, revealing how Cas12a accomplishes DNA-guided RNA recognition. The ΨDNA hairpin bridges the recognition and nuclease lobes, mimicking a PAM-proximal duplex and positioning the spacer to allow formation of a canonical RNA-DNA heteroduplex along the REC lobe. This provides a structural framework for its activity and provides a blueprint for future engineering.
Authors
- Carlos Orosco
- David Ward Taylor (ORCID: https://orcid.org/0000-0002-6198-1194)
- Rodrigo Fregoso Ocampo (ORCID: https://orcid.org/0009-0006-0951-8975)
- Boyu Huang (ORCID: https://orcid.org/0000-0003-2646-7656)
- Piyush Jain (ORCID: https://orcid.org/0000-0001-7153-442X)
- M. Stewart West (ORCID: https://orcid.org/0009-0007-6299-5145)
Institutions
- Livestrong Foundation (US)
- University of Florida Health (US)
- University of Florida (US)
- The University of Texas at Austin (US)
Publication Details
- Journal
- bioRxiv (Cold Spring Harbor Laboratory)
- Published
- 2026-03-20
- DOI
- https://doi.org/10.64898/2026.03.19.712971
- Primary Topic
- CRISPR and Genetic Engineering
- Type
- article
- Field-Weighted Citation Impact
- 0.00