Ribosomal structure research with polarized neutron scattering

Abstract Polarized neutron scattering from dynamically polarized nuclear spin targets has become a method of macromolecular structure research. The contrast created by substitution of the hydrogen isotope 1 H by 2 H is increased by almost a factor of three if polarized neutrons are scattered by polarized nuclear spins in the sample (spin contrast variation). Therefore, this method is also suitable to determine small or weakly contrasted labels. Proteins with a mass less than 1 wt% of the background particle were localized. In this paper, the extended version of protein localization is presented: proteins L1, L2, L3, L4 in 50 S and proteins S6, S10 in 70 S. Furthermore, even the position of two weakly contrasted tRNAs bound at the elongating 70 S ribosome were determined.