Anthropic's biology research team, leveraging its AI model Claude, completed the first three-dimensional cryo-EM structure of a prokaryotic vault particle assembled from phage-derived L05 protein. The structure comprises 96 protein copies (48 per half-shell), weighs approximately 9.5 megadaltons, and measures about 54 nm × 45 nm, with an internal volume roughly 25% larger than mammalian vaults. The team reported that Claude-assisted workflows compressed the purification process from approximately three days to about 90 minutes, while the initial structural model was generated in roughly 34 hours. The biological function of the vault particle remains unknown. A preprint of the findings has been submitted to bioRxiv.