dense gels of e. coli 70 s ribosomes , their 50 s subunits , cm-like particles , rnp strands and their fragments , 38 s particles obtained from rnp strand folding upon addition of mg2+ ions , and of unoriented salt-free and free rrna sodium and magnesium salts were studied by x-ray diffraction .
C0035553
ribosomes
C0035701
rrna