Ribosomes deprived of select proteins show similar structural alterations induced by thermal treatment of native particles

Three different techniques-light scattering, radiowave dielectric spectroscopy, and fluorescence-were employed to investigate conformational variations in Escherichia coli ribosomes induced by removal of specific proteins. To this end, particles were treated with lithium chloride at different ion strength values to produce ribosomal cores. It was previously observed that treatment of ribosomes to subdenaturing temperatures promotes a structural rearrangement that implies a higher exposure of ribosomal RNA to the solvent. Results presented here strongly suggest that protein elimination from the ribosomal particle produces an overall response recalling the same variation of physical parameters previously observed after thermal treatment. We therefore suggest that high salt treatment produces the same structural modification caused by exposure to subdenaturing temperatures.