Structural snapshots of the cytosolic and mitochondrial mRNA translation machineries in kinetoplastids
mRNA translation is a universally conserved process consisting on translating the genetic code into proteins. Translation is mainly operated by the ribosome and because of its essentiality, it is the target of numerous prescribed antibiotics, in part thanks to the large structural and functional discrepancies between the bacterial and human ribosomes. However, when the pathogen is a eukaryotic organism, such as a kinetoplastid (e.g., trypanosomes and leishmania), this strategy become difficult to apply, because of the conservation of the eukaryotic ribosome. Among the most infamously known kinetoplastids related to human health, Trypanosoma cruzi and Leishmania major, responsible of the Chagas disease and various leishmaniasis. While it is accepted that the eukaryotic ribosome is highly conserved, substantial species-specific structural and regulatory differences can exist among eukaryotes, especially in the case of mitochondrial ribosomes that are highly specialized and only translates a dozen proteins most of which are subunits of the respiratory chain complexes. I will describe some of the kinetoplastids-specific features of cytosolic and mitochondrial mRNA translation, which were unveiled mainly thanks to structural biology and the use of cryogenic electron microscopy (cryo-EM).
