The spatial arrangement of the complex between eukaryotic initiation factor eIF-3 and 40 S ribosomal subunit....

The binding site for eIF-3 on the small ribosomal subunit was studied (a) by use of a complex of eIF-3 and derived 40 S ribosomal subunit from rat liver, and (b) by use of native small ribosomal subunits from rabbit reticulocytes. After treatment of both complexes with dimethyl 4,7-dioxo-5,6-dihydroxy-3,8-diazadecanbisimidate ribosomal proteins S3a, S4, S6, S7, S8, S9, S10, S23/24 and S27 became covalently linked to eIF-3 and were isolated together with the factor by gradient centrifugation. The ribosomal proteins were identified by two-dimensional polyacrylamide gel electrophoresis after periodate cleavage of the link(s).