Deep-ocean metagenome yields cold-adapted Cas9 nuclease with high specificity at low temperatures

Researchers report the characterisation of Deep Ocean 1 Cas9 (DO1Cas9), described in a bioRxiv preprint as the first Cas9-family nuclease recovered from the deep ocean. The enzyme was isolated from a metagenomic sample collected at approximately 1,500 m depth in the Atlantic Ocean.

DO1Cas9 displays several properties that distinguish it from Streptococcus pyogenes Cas9 (SpCas9), the most widely deployed CRISPR nuclease. The enzyme exhibits cold-adapted structural flexibility, retains efficient double-stranded DNA cleavage activity at temperatures where SpCas9 is largely inactive, and shows higher on-target specificity than SpCas9 under the conditions tested. The authors also report that DO1Cas9 stability is influenced by salt concentration. In cell-based experiments, the enzyme successfully edited genomes in cultured cells.

The findings have potential relevance for CRISPR applications that require activity at lower temperatures — including certain ex vivo cell-engineering protocols, environmental biotechnology contexts, and applications in cold-adapted organisms — though all such uses would require substantial further development and optimisation.

This work has not yet undergone peer review. As with all preprints, findings should be treated as preliminary until independently validated and published in a peer-reviewed journal.