As befits an immune mechanism, CRISPR-Cas systems are highly variable with respect to
Cas protein sequences, gene composition, and organization of the genomic loci. Optimal …

Bacteria and their viral predators (bacteriophages) are locked in a constant battle. In order to
proliferate in phage-rich environments, bacteria have an impressive arsenal of defence …

REBASE is a comprehensive and fully curated database of information about the
components of restriction-modification (RM) systems. It contains fully referenced information …

The evolutionary pressure imposed by phage predation on bacteria and archaea has
resulted in the development of effective anti-phage defence mechanisms, including …

Evolution of bacteria and archaea involves an incessant arms race against an enormous
diversity of genetic parasites. Accordingly, a substantial fraction of the genes in most …

DNA methylation acts in concert with restriction enzymes to protect the integrity of
prokaryotic genomes. Studies in a limited number of organisms suggest that methylation …

Restriction-modification (RM) systems are ubiquitous and are often considered primitive
immune systems in bacteria. Their diversity and prevalence across the prokaryotic kingdom …

Our knowledge of prokaryotic defense systems has vastly expanded as the result of
comparative genomic analysis, followed by experimental validation. This expansion is both …

Bacteria, the most abundant organisms on the planet, are outnumbered by a factor of 10 to 1
by phages that infect them. Faced with the rapid evolution and turnover of phage particles …

The roles of restriction-modification (RM) systems in providing immunity against horizontal
gene transfer (HGT) and in stabilizing mobile genetic elements (MGEs) have been much …