capping by ancient eukaryotes

UB Department of Biological Sciences: Kiong Ho: "Initial analysis of the mRNA capping apparatus of T. brucei and the malarial parasite P. falciparum has illuminated an evolutionary connection to fungi rather than metazoans. T. brucei and P. falciparum encode a triphosphatase that is structurally and mechanistically similar to the fungal enzymes. RNA triphosphatase is an attractive drug target because the mechanism of cap formation is completely different from the metazoan host and metazoan species encode no recognizable homologue of the fungal/protozoan enzymes. Thus, a mechanism-based inhibitor against triphophatase should be highly selective for the parasite and have minimal effect on the human host or arthropod vector."