The bacterial toxin ReIE induces specific mRNA cleavage in the A site of the eukaryote ribosome

ReIE/ReIB is a well-characterized toxin-anti-toxin pair involved in nutritional stress responses in Bacteria and Archae. ReIE lacks any eukaryote homolog, but we demonstrate here that it efficiently and specifically cleaves mRNA in the A site of the eukaryote ribosome. The cleavage mechanism is similar to that in bacteria, showing the feasibility of A-site cleavage of mRNA for regulatory purposes also in eukaryotes. ReIE cleavage in the A-site codon of a stalled eukaryote ribosome is precise and easily monitored, making ReIE printing a useful complement to toeprinting to determine the exact mRNA location on the eukaryote ribosome and to probe the occupancy of its A site.