| The ribosome is one of the most complex cellular structures. Several functional centers have been located on the ribosome, one of which is the GTPase center. An important part of this center is protein L11, which was found to support tertiary structure of a small domain of rRNA. L11 is important, but not crucial, for ribosomal function. A lot of biochemical and structural information is available for bacterial L11.; Structural and functional information for the eukaryotic counterpart of L11 is very scarce. Phylogenetic analyses shows that bacterial and eukaryotic L11 are somewhat conserved, but contain regions of very different sequence. On the other hand, the molecular target of L11, a 58 nucleotide piece of 23S, 25S or 28S rRNA, is extremely conserved between all phylogenetic domains. Here we characterize a cloned and overexpressed homolog of L11 from Saccharomyces cerevisiae in regard to its interactions with rRNA from bacterial and eukaryotic sources.; The GTPase center is also an area of ribosome interaction with several antibiotics, the best studied of which is thiostrepton. For a long time it was thought that thiostrepton interacts with bacterial rRNA only and that small differences in primary structure between bacterial and eukaryotic rRNA prevent the antibiotic from acting on eukaryotic ribosomes. We present evidence that differences in bacterial and eukaryotic L11 is probably a more important factor than RNA sequence differences in antibiotic activity. |
