Anthropic says Claude found a CRISPR-like enzyme system in phage DNA whose function is still unknown

Anthropic announced that Claude identified a previously undescribed enzyme system in the DNA of bacteriophages, the viruses that infect bacteria. It is the first result from a molecular biology group and wet lab the company formed this spring. Anthropic says Claude did the work with only high-level direction from its scientists. The team calls the system array-associated reverse transcriptases, or ART. It has three parts: a reverse transcriptase enzyme, a partner gene next to it, and an array of 3 to 21 evenly spaced DNA repeats. The layout resembles a CRISPR array, but the preprint reports that none of the systems carry the cas genes found near CRISPR systems. In lab tests, the array was read out as a set of distinct short RNAs. In published data from a Staphylococcus phage, those RNAs made up as much as 8% of the phage's RNA 15 minutes after infection. The preprint has not been peer reviewed. It also says the team has not yet shown that the enzyme is active or that it acts on these RNAs. Anthropic CEO Dario Amodei wrote on X that the discovery was made "mostly, though not entirely, by Claude." He also acknowledged that a Stanford team had previously found a system that is similar in some ways. Other researchers will need to validate how new the finding is.