Rhs toxins
Rhs toxins belong to the polymorphic toxin category of bacterial exotoxins. Rhs proteins are widespread and can be produced by both Gram-negative and Gram-positive bacteria. Rhs toxins are very large proteins of usually more than 1,500 aminoacids with variable C-terminal toxic domains. Their toxic activity can either target eukaryotes or other bacteria.
Domain architecture
In their large N-terminal region, Rhs toxins comprise RHS/YD repeats in various number and another "RHS-repeats associated core" domain. In contrast, their C-terminal regions are shorter and harbor highly variable C-terminal domains including many domains with a predicted nuclease activity.Function
Anti-eukaryotic activity
These toxins encompass Rhs toxins of insect pathogens with an activity against insects. This group also include Rhs toxins with an activity against human phagocytic cells that contribute to pathogenesis of Pseudomonas aeruginosa.Anti-bacterial activity
A role in inter-bacterial competition has been demonstrated for the plant pathogen Dickeya dadantii and for the human pathogen Escherichia coli.When a polymorphic toxin with anti-bacterial activity is produced by a bacterial strain, this strain is protected by a specific immunity protein encoded by a gene immediately downstream of the toxin gene.