Protein-RNA associations were studied by a method using proteins blotted on a nitrocellulose sheet. This method was assayed with Escherichia Coli 30S ribosomal components. In stringent conditions (300 mM NaCl or 20" C) only 9 E. coli ribosomal proteins strongly bound to the 16S rRNA: S4, S5, S7, S9, S127~ST3^~S14, S19, S20. 8 of these proteins have been previously found to bind independently to...

Mutants of an archaeon Halobacterium halobium, resistant to the universal inhibitor of translation, pactamycin, were isolated. Pactamycin resistance correlated with the presence of mutations in the 16 S rRNA gene of H. halobium single rRNA operon. Three types of mutations were found in pactamycin resistant cells, A694G, C795U and C796U (Escherichia coli 16 S rRNA numeration) located distantly i...

Specific ribonucleotides within the 5' domain of Escherichia coli 16 S rRNA were altered by deletion and/or substitution by site-directed mutagenesis of cloned DNA to assess the importance of these particular residues in defining the binding site for ribosomal protein S20. Gel filtration and sucrose gradient centrifugation were employed to measure the binding of ribosomal protein S20 to synthet...