Direct CRISPR spacer acquisition from RNA by a natural reverse transcriptase–Cas1 fusion protein

CRISPR-Cas captures invading RNA The CRISPR (clustered regularly interspaced short palindromic repeat) system provides bacteria with an adaptive immune response. DNA captured from viruses and plasmids by CRISPR-associated protein 1 (Cas1) is used by bacteria to target the invaders' for destruction. Silas et al. discover that certain classes of the Cas1 gene are fused to a reverse transcriptase gene ( RT-Cas1 ) (see the Perspective by Sontheimer...