ИСТИНА

Transition between different stages of the ribosome working cycle is strictly coordinated by changes in structure and mutual position both of ribosome subunits and their ligands.Therein, information regarding these structural transformations is transmitted through specific signals. Since a distance between functional centers of the ribosome is reaching up to several tens of angstroms, it is believed that such signals are transduced allosterically. In our study, we attempted to answer the question of how allosteric signal can be transmitted fromthe so-called sensory elements of ribosomal tunnel (RT) to the peptidyl transferase center (PTC). A segment of RT wall from the E.coli ribosome composed of nucleotide residues A2058, A2059, 2mA2503, G2061, A2062 and C2063 of 23S rRNA was examined by molecular dynamics simulations. It was found that a potential signal tansduction pathway A2058 - C2063 acted as a dynamic ensemble of interdependent conformational states, wherein cascade-like changes can occur. We assume that these structural rearrangements results in reversible inactivation of PTC due to strong stacking contact between its residues U2585 and C2063. A potential role of the observed conformational transitions for regulating ribosome activity is discussed.