On the structure of native small ribosomal subunits and initiation factor eIF-3 isolated from rat liver.

The three-dimensional structure of initiation factor eIF-3 and its binding site on native small ribosomal subunits have been analyzed by electron microscopic studies of native small ribosomal subunits and of initiation factor eIF-3 prepared from rat liver as well as by hydrodynamic studies of isolated eIF-3. Initiation factor eIF-3 has the shape of a flat triangular prism and is bound with its triangular base to the body part of the convex rear side of the small ribosomal subunit.