Distinguishing self from non-self is a vital function for immune systems to repel invaders without inducing autoimmunity. One system, which protects bacteria and archaea from invasion by phage and plasmid DNA, involves clustered, regularly interspaced, short palindromic repeat (CRISPR) loci. Here, in Staphylococcus epidermidis, the mechanism of CRISPR self/non-self discrimination is defined.
- Luciano A. Marraffini
- Erik J. Sontheimer