Study of the internal structure of Escherichia coli ribosomes by neutron and X-ray scattering

摘要: Neutron scattering curves of the small and large subparticles Escherichia coli ribosomes are presented over a wide range angles for several contrasts. It was verified that native ribosome structure not affected by 2H2O in buffer. The reliability neutron curves, obtained H2O buffer, established X-ray experiments on same material. The non-homogeneous distribution RNA protein E. is confirmed, with predominantly within particle its periphery. distances between centres gravity components do exceed 25 A 30 A, subparticles, respectively. The volume occupied determined. ratio “dry” to found be 0.56; it both subparticles. Such packing characteristic single helices ribosomal at their crystallization transfer crystals. conclusion drawn similar state. Experimental subparticle depend significantly contrast angular region which mainly determined shape. curve, as infinite approached, calculated observed electron microscopy. Thus, long-existing contradiction microscopy data (an elonggated an axial 2:1) oblate 1:3.5), concerning overall shape S subparticle, settled favour experimental curve well-described V-like model proposed recently Vasiliev et al. (1978). Experimental given support hypothesis maxima corresponding Bragg 90 20 arise from component alone. shown prominence peaks this depends only fraction component. can changed using “native contrast” (ribosomal particles containing different amounts protein) varying solvent composition. most pronounced where highest or solvents density matched solvent. vectors however, remain unchanged. This allows us propose tight common principle structural arrangement ribosomes.