In situ structure determination of the ribosomal protein L14 in the large 50S subunit of Escherichia coli

Polarized neutron scattering from dynamically polarized nuclear spin target s has become a method of macromolecular structure research. The contrast cr eated by substitution of the hydrogen isotope H-1 by H-2 is increased by al most a factor of three if polarized neutrons are scattered by polarized nuc lear spins in the sample (spin contrast variation). Therefore, this method is also suitable to determine small or weakly contrasted labels. Proteins w ith a mass less than 1 wt.% of the background particle were localized. In t his paper, an extension of our structural model for the 50S subunit by the in situ structure determination of the protein L14 is presented.