Bacteriophage Cooperation Suppresses CRISPR-Cas3 and Cas9 Immunity.

ABSTRACT: Bacteria utilize CRISPR-Cas adaptive immune systems for protection from bacteriophages (phages), and some phages produce anti-CRISPR (Acr) proteins that inhibit immune function. Despite thorough mechanistic and structural information for some Acr proteins, how they are deployed and utilized by a phage during infection is unknown. Here, we show that Acr production does not guarantee phage replication when faced with CRISPR-Cas immunity, but instead, infections fail when phage population numbers fall below a critical threshold. Infections succeed only if a sufficient Acr dose is contributed to a single cell by multiple phage genomes. The production of Acr proteins by phage genomes that fail to replicate leave the cell immunosuppressed, which predisposes the cell for successful infection by o

SUBMITTER: Borges AL 

PROVIDER: S-EPMC6086726 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature