Differences in 23 S rRNA-protein neighbourhood in Escherichia coli 70 S ribosomes and 70 S initiation complex Probing by bifunctional Pt(III)-containing reagent

AbstractrRNA-protein cross-links in free E. Coli35S-labeled 70 S ribosomes and in the initiation complex 35-labeled 70 S ribosome · AUGU6 · Metf-tRNAMetf were studied with the aid of a new type of binuclear (PtII) compound — dichlorotetra-ammine (1,6-hexamethylenediaminediplatinum) dichloride. The use of this reagent allowed us to reveal differences in the rRNA-protein neighbourhood in free 70 S ribosomes and in the initiation complex. Proteins L3, L6, L23 and L25 were shown to cross-link to 23 S rRNA only in the initiation complex, whereas proteins L1, L13, L14, L16. L17, L18, L22, L28 and S1 did so in both free ribosomes and the complex. 16 S rRNA was found to be cross-linked preferentially to a single protein, S1, in both states of the ribosomes