“The Widespread IS200/605 Transposon Family Encodes Diverse Programmable RNA-Guided Endonucleases”, 2021-09-09 (; similar):
[Twitter] IscB proteins are putative nucleases encoded in a distinct family of IS200/IS605 transposons and are likely ancestors of the RNA-guided endonuclease Cas9, but the functions of IscB and its interactions with any RNA remain uncharacterized.
Using evolutionary analysis, RNA-seq, and biochemical experiments, we reconstruct the evolution of CRISPR-Cas9 systems from IS200/IS605 transposons. We show that IscB uses a single non-coding RNA for RNA-guided cleavage of double-stranded DNA and can be harnessed for genome editing in human cells. We also demonstrate the RNA-guided nuclease activity of TnpB, another IS200/605 transposon-encoded protein and the likely ancestor of Cas12 endonucleases.
This work reveals a widespread class of transposon-encoded RNA-guided nucleases, which we name OMEGA (Obligate Mobile Element Guided Activity), with strong potential for developing as biotechnologies.