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bioRxiv · 10.1101/2021.08.16.456562

Metagenomic Discovery of CRISPR-Associated Transposons

Rybarski, J. R.·Hu, K.·Hill, A. M.·Wilke, C. O.·Finkelstein, I. J.
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Abstract

CRISPR-associated transposons (CASTs) co-opt Cas genes for RNA-guided transposition. CASTs are exceedingly rare in genomic databases; recent surveys have reported Tn7-like transposons that co-opt Type I-F, I-B, and V-K CRISPR effectors. Here, we expand the diversity of reported CAST systems via a bioinformatic search of metagenomic databases. We discover new architectures for all known CASTs, including novel arrangements of the Cascade effectors, new self-targeting modalities, and minimal V-K systems. We also describe new families of CASTs that have co-opted the Type I-C and Type IV CRISPR-Cas systems. Our search for non-Tn7 CASTs identifies putative candidates that co-opt Cas12a for horizontal gene transfer. These new systems shed light on how CRISPR systems have co-evolved with transposases and expand the programmable gene editing toolkit.

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Rybarski, J. R., Hu, K., Hill, A. M., Wilke, C. O., Finkelstein, I. J.. 2021-08-16. Metagenomic Discovery of CRISPR-Associated Transposons. https://doi.org/10.1101/2021.08.16.456562

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