title: Genetic reconstruction of protozoan rRNA decoding sites provides a rationale for paromomycin activity against Leishmania and Trypanosoma.
abstract: Aminoglycoside antibiotics target the ribosomal decoding A-site and are active against a broad spectrum of bacteria. These compounds bind to a highly conserved stem-loop-stem structure in helix 44 of bacterial 16S rRNA. One particular aminoglycoside, paromomycin, also shows potent antiprotozoal activity and is used for the treatment of parasitic infections, e.g. by Leishmania spp. The precise drug target is, however, unclear; in particular whether aminoglycoside antibiotics target the cytosolic and/or the mitochondrial protozoan ribosome. To establish an experimental model for the study of protozoan decoding-site function, we constructed bacterial chimeric ribosomes where the central part of bacterial 16S rRNA helix 44 has been replaced by the corresponding Leishmania and Trypanosoma rRNA sequences. Relating the results from in-vitro ribosomal assays to that of in-vivo aminoglycoside activity against Trypanosoma brucei, as assessed in cell cultures and in a mouse model of infection, we conclude that aminoglycosides affect cytosolic translation while the mitochondrial ribosome of trypanosomes is not a target for aminoglycoside antibiotics.
authors.affiliation: Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland.
authors.forename: Sven N
authors.initials: SN
authors.lastname: Hobbie
authors.forename: Marcel
authors.initials: M
authors.lastname: Kaiser
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schmidt
authors.forename: Dmitri
authors.initials: D
authors.lastname: Shcherbakov
authors.forename: Tanja
authors.initials: T
authors.lastname: Janusic
authors.forename: Reto
authors.initials: R
authors.lastname: Brun
authors.forename: Erik C
authors.initials: EC
authors.lastname: Böttger
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D004195:Disease Models, Animal; D005260:Female; D007891:Leishmania / Q000187:drug effects*; D051379:Mice; D021261:Parasitic Sensitivity Tests; D010303:Paromomycin / Q000494:pharmacology*; D014176:Protein Biosynthesis / Q000187:drug effects*; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D016053:RNA, Protozoan / Q000235:genetics / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic; D012376:Rodent Diseases / Q000188:drug therapy / Q000469:parasitology; D014346:Trypanosoma brucei brucei / Q000187:drug effects*; D014353:Trypanosomiasis, African / Q000188:drug therapy / Q000469:parasitology
chemical_list: D000981:Antiprotozoal Agents; D012329:RNA, Bacterial; D016053:RNA, Protozoan; D012335:RNA, Ribosomal; D010303:Paromomycin