[Internal structure of ribosomes using different types of emission]

Abstract

A review is made of the experimental results obtained by the author and co-workers on the study of the structural organization of the RNA and the protein in ribosomes by the method of joint use of light, X-ray and neutron scattering and by the method of contrast variation in neutron scattering. Two rules are formulated for the folding of the ribonucleoprotein strand in ribosomes: (1) in each ribosomal subparticle the RNA is concentrated predominantly closer to the center of the particle whereas the protein has a more peripherical localization; (2) the compact ("crystallic") packing of hydrated RNA helices is an essential feature of the nucleus (nuclei) organization of the particles. An analysis of the experimental data on neutron scattering by ribosomal proteins has been done and the globulin conformation in solution of some of these proteins has been established. The widespread concept according to which the majority of ribosomal proteins on the ribosome and in solution are enlongated expanded structures is disputed. It is suggested that all, or almost all, ribosomal proteins are usual globular proteins recognizing the specific sequence of RNA on the periphery of the particles, and , hence, that the formation of functional centrers on the ribosome is, in principle, analogous to the formation of functional centers of other complex proteins with a quaternary structure.