Plasmid pXO1

Plasmid pXO1 is a circular piece of DNA found in the bacterium Bacillus anthracis, which causes anthrax. Unlike the bacterium's main chromosome, pXO1 carries genes responsible for producing key toxins that make the infection dangerous. These toxin genes enable the bacterium to damage host cells and evade the immune system. Because pXO1 is crucial for producing these virulence factors, studying it helps scientists understand anthrax and develop vaccines or treatments. Essentially, pXO1 acts as a genetic blueprint for the bacterium’s deadly toxins.