RNA-directed Cleavage and Modification of DNA using CasX (CRISPR-CasX)

Tech ID: 26042 / UC Case 2017-016-0

Patent Status

Country Type Number Dated Case
United States Of America Issued Patent 11,873,504 01/16/2024 2017-016
India Issued Patent 462184 10/26/2023 2017-016
United States Of America Issued Patent 11,795,472 10/24/2023 2017-016
United Kingdom Issued Patent 2569733 09/14/2022 2017-016
United States Of America Issued Patent 10,570,415 02/25/2020 2017-016
United States Of America Published Application 20240167052 05/23/2024 2017-016
Mexico Published Application WO 2018/064371 02/25/2021 2017-016
Hong Kong Published Application 40012328A 07/24/2020 2017-016
Hong Kong Published Application 40004835 A 04/29/2020 2017-016
Japan Published Application 2019-532644 11/14/2019 2017-016
Eurasian Patent Office Published Application 201990861 09/30/2019 2017-016
European Patent Office Published Application 3523426 A0 08/14/2019 2017-016
China Published Application CN110023494A 07/16/2019 2017-016
Brazil Published Application 2529 06/25/2019 2017-016
Rep Of Korea Published Application 10-2019-0071725 06/24/2019 2017-016
Australia Published Application WO 2018/064371 04/05/2018 2017-016
Canada Published Application WO 2018/064371 04/05/2018 2017-016
Israel Published Application WO 2018/064371 04/05/2018 2017-016
New Zealand Published Application WO 2018/064371 04/05/2018 2017-016
Saudi Arabia Published Application WO 2018/064371 04/05/2018 2017-016
Singapore Published Application WO 2018/064371 04/05/2018 2017-016
South Africa Published Application WO 2018/064371 04/05/2018 2017-016

Additional Patents Pending

Brief Description

The CRISPR-Cas system is now understood to confer bacteria and archaea with acquired immunity against phage and viruses. CRISPR-Cas systems consist of Cas proteins, which are involved in acquisition, targeting and cleavage of foreign DNA or RNA, and a CRISPR array, which includes direct repeats flanking short spacer sequences that guide Cas proteins to their targets.  Class 2 CRISPR-Cas are streamlined versions in which a single Cas protein bound to RNA is responsible for binding to and cleavage of a targeted sequence. The programmable nature of these minimal systems has facilitated their use as a versatile technology that is revolutionizing the field of genome manipulation.  Current CRISPR Cas technologies are based on systems from cultured bacteria, leaving untapped the vast majority of organisms that have not been isolated.  There is a need in the art for additional Class 2 CRISPR/Cas systems (e.g., Cas protein plus guide RNA combinations).


UC Berkeley researchers discovered a new type of Cas protein, CasX, from groundwater samples. CasX is short compared to previously identified CRISPR-Cas endonucleases, and thus use of this protein as an alternative provides the advantage that the nucleotide sequence encoding the protein is relatively short.  CasX utilizes a tracrRNA and a guide RNA to perform double stranded cleavage of DNA. The researchers introduced CRISPR-CasX into E. coli, finding that they could block genetic material introduced into the cell.  Further research results indicated that CRISPR-CasX operates in a manner analogous to CRISPR-Cas9, but utilizing an entirely distinct protein architecture containing different catalytic domains.   CasX is also expected to function under different conditions (e.g., temperature) given the environment of the organisms that CasX was expressed in.  Similar to CRISPR Cas9, CasX enzymes are expected to have a wide variety of applications in genome editing and nucleic acid manipulation. 

Suggested uses

  • Diagnostics



  • Functions under different conditions than currently used CRISPR-Cas proteins (e.g., lower temperatures)
  • Nucleotide sequence encoding the CasX protein is short



CasX enzymes comprise a distinct family of RNA-guided genome editors: Jun-Jie Liu, Natalia Orlova, Benjamin L. Oakes, Enbo Ma, Hannah B. Spinner, Katherine L. M. Baney, Jonathan Chuck, Dan Tan, Gavin J. Knott, Lucas B. Harrington, Basem Al-Shayeb, Alexander Wagner, Julian Brötzmann, Brett T. Staahl, Kian L. Taylor, John Desmarais, Eva Nogales & Jennifer A. Doudna, Nature, volume 566, pages218–223 (2019) 

New CRISPR–Cas systems from uncultivated microbes 

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  • Doudna, Jennifer A.

Other Information


CRISPR, gene editing, genome, gene therapy, cell biology, CasX, Cas12e

Categorized As

Additional Technologies by these Inventors