THIOSTREPTON BINDS TO MALARIAL PLASTID RIBOSOMAL-RNA

Binding of the thiazolyl peptide antibiotic thiostrepton to the GTPase domain of 23S rRNA involves a few crucial nucleotides, notably A1067 (E. coli). Small RNA transcripts were prepared corresponding to the GT Pase domain of the plastid 23S rRNA and the two forms of cytosolic 28S rRNAs found in the human malaria parasite Plasmodium falciparum, as w ell as the plastid form of rRNA of the AIDS-related pathogen Toxoplasm a gondii. Binding affinities of the wild type and mutated RNA sequence s were as predicted; the malarial plastid sequence had by far the high est affinity, whereas that from toxoplasma did not bind thiostrepton. (C) 1997 Federation of European Biochemical Societies.