Structure of protein-deficient 50 S ribosomal subunits. Particles without 5 S RNA-protein complex retain the L7/L12 stalk and associate with 30 S subunits.

50 S ribosomal subunit derivatives without the 5 S RNA-protein complex obtained either by splitting with EDTA or by reconstitution from the 23 S RNA and proteins have been studied by electron microscopy. Removal of the 5 S RNA-protein complex is shown to affect neither the overall morphology of the larger ribosomal subunit nor the mode of its association with the small subunit.