The in situ structure of the L3 and L4 proteins of the large subunit of E. coli ribosomes as determined by nuclear spin contrast variation

Abstract
Polarized Neutron scattering from dynamically polarized targets has been used to determine the in situ structure of the proteins L3 and L4 of the large subunit of E.coli ribosome. Both proteins (M≈2.3*10⁴) have an elongated shape and radii of gyration of about 19 Å. The orientation of the proteins with respect to that of the ribosomal subunit has been determined. The distance between the centers of mass of L3 and L4 amounts to 125±10 Å.