CRISPR-CasΦ from huge phages is a hypercompact genome editor

Patrick Pausch, Basem Al-Shayeb, Ezra Bisom-Rapp, Connor A. Tsuchida, Zheng Li, Brady F. Cress, Gavin J. Knott, Steven E. Jacobsen, Jillian F. Banfield, Jennifer A. Doudna

Research output: Contribution to journalArticleResearchpeer-review

86 Citations (Scopus)


CRISPR-Cas systems are found widely in prokaryotes, where they provide adaptive immunity against virus infection and plasmid transformation. We describe a minimal functional CRISPR-Cas system, comprising a single ~70-kilodalton protein, CasΦ, and a CRISPR array, encoded exclusively in the genomes of huge bacteriophages. CasΦ uses a single active site for both CRISPR RNA (crRNA) processing and crRNA-guided DNA cutting to target foreign nucleic acids. This hypercompact system is active in vitro and in human and plant cells with expanded target recognition capabilities relative to other CRISPR-Cas proteins. Useful for genome editing and DNA detection but with a molecular weight half that of Cas9 and Cas12a genome-editing enzymes, CasΦ offers advantages for cellular delivery that expand the genome editing toolbox.

Original languageEnglish
Pages (from-to)333-337
Number of pages5
Issue number6501
Publication statusPublished - 17 Jul 2020

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