[Affinity labeling of the ribosomes from Escherichia coli by 4-(N-2-chloroethyl-N-methyl-aminobenzyl-5'-phosphoamide of heptauridylic acid].

4-(N-2-chloroethyl-N-methyl)aminobenzyl-5'-phosphoamide of the heptauridylic acid was used to localize the structures organizing mRNA-binding site of ribosomes from E. coli. Both rRNA and proteins undergo modification in the ribosome 10-18 and 82-90% of the total ribosomal subunit modification, respectively. Using the method of two-dimensional electrophoresis in the acrylamide gel the proteins S5, S11, S13 and L2, L7/L12, L31 which are labelled by the analog of mRNA were identified. We assume these proteins to be located in the vicinity of mRNA-binding centre of ribosomes.