We present the evolutionary origin of a new class of tRNA-guanine transglycosylases.
These enzymes horizontally acquired by eukaryotic microbes from Chlamydiae bacteria.
Drugs have been developed against bacterial tRNA-guanine transglycosylases.
The presence of these enzymes in pathogenic protozoa serve as putative drug targets.
Horizontal gene transfer represents are untapped resource for possible drug targets.