The PrrC system protects bacteria against phages via an abortive infection. It is composed of a single effector protein, but relies on the presence of a full type Ic restriction-modification system in the vicinity. PrrC proteins are therefore typically found embedded in a larger RM system.
## Molecular mechanism
The effector protein prrC complements a RM system by cutting tRNALys in the anticodon loop, upstream of the wobble nucleotide and causes the arrest of phage protein synthesis and phage growth.
prrC serves as a guardian of the acrivity of EcoprrI, which can be inactivated by the Stp peptide of phage T4 at the beginning of infection. Inactivation of EcoprrI by Stp induces a conformation change that in turn activates PrrC, releasing its nuclease activity and stalling host and phage growth :ref{doi=10.1006/jmbi.1995.0343}.
Because it sabotages the host's translation machinery, prrC is considered to be an abortive infection system.
## Example of genomic structure
The PrrC system is composed of 4 proteins: EcoprrI, Type_I_S, PrrC and, Type_I_REases.
