CRISPR-CasΦ from huge phages is a hypercompact genome editor
Authors: Gavin J Knott
Connor A Tsuchida
Steven E Jacobsen
Basem Al-Shayeb
Brady F Cress
Ezra Bisom-Rapp
Jillian F Banfield
Zheng Li
Jennifer A Doudna
Patrick Pausch
Journal: Science (2020)
Discipline: Multidisciplinary
Keywords: CRISPR-Cas systems; prokaryotes; adaptive immunity; virus infection; plasmid transformation
Affiliations: Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA., Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA., Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA., College of Natural Resources, University of California, Berkeley, Berkeley, CA, USA., University of California, Berkeley-University of California, San Francisco Graduate Program in Bioengineering, Berkeley, CA, USA., Department of Molecular, Cellular and Developmental Biology, University of California, Los Angeles, CA, USA., Monash Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia., Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA., Department of Earth and Planetary Sciences, University of California, Berkeley, Berkeley, CA, USA., Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA. ., Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA., Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA., Gladstone Institute of Data Science and Biotechnology, Gladstone Institutes, San Francisco, CA, USA.

Abstract:  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. 

Retracted: No

PubPeer comments:
 How do you know this is a phage?  Genome sequences that were clearly not bacterial, archaeal, archaeal virus, eukaryotic or eukaryotic virus were classified as phage, plasmid-like or mobile genetic elements of uncertain nature on the basis of their gene inventories How do you know it is  clearly not bacterial, ... ? It may be a yet unknown bacteria, archaea... Just because it assembles into a large contig? Have you infected a bacteria with this virus? Metagenomic data is never good for assembling genomes, unless it really small (like Cov2, even then many metagenomes dont give you a full one) Why would the genome of the supposed phage (SR-VP_PHAGE_CIR_63_141.gbk) have all these varied bacterial genes - sometimes with very high homology? They have basically assembled some sort of a Spirochaetes (a bacteria) - at least in part... ![file] , 
 This is CRISPR - but from a bacteria... , 
 Sandeep. Where is this file of yours: SR-VP_PHAGE_CIR_63_141.gbk ? , 
 Brian, its in the SI of their previous paper...  Genbank files for all genome https: www.nature.com articles s41586-020-2007-4#Sec22 You can link this genome to the current paper from [the SI](http: science.sciencemag.org content suppl 2020 07 15 369.6501.333.DC1) - which lists the Cas proteins , 
 any one found that the cas12j caused more C to T and G to A than indels? ,