Antibiotic interactions at the GTPase-associated centre within Escherichia coli 23S rRNA.

AUTOR(ES)

Egebjerg, J

RESUMO

A comprehensive range of chemical reagents and ribonucleases was employed to investigate the interaction of the antibiotics thiostrepton and micrococcin with the ribosomal protein L11-23S RNA complex and with the 50S subunit. Both antibiotics block processes associated with the ribosomal A-site but differ in their effects on GTP hydrolysis, which is inhibited by thiostrepton and stimulated by micrococcin. The interaction sites of both drugs were shown to occur within the nucleotide sequences A1067-A1098 within the protein L11 binding site on 23S RNA. This region of the ribosome structure is involved in elongation factor-G-dependent GTP hydrolysis and in the stringent response. No effects of drug binding were detected elsewhere in the 23S RNA. In general, the two drugs afforded 23S RNA similar protection from the chemical and nuclease probes in accord with their similar modes of action. One important exception, however, occurred at nucleotide A1067 within a terminal loop where thiostrepton protected the N-1 position while micrococcin rendered it more reactive. This difference correlates with the opposite effects of the two antibiotics on GTPase activity.

Documentos Relacionados

• The environment of 5S rRNA in the ribosome: cross-links to the GTPase-associated area of 23S rRNA.
• Higher order interactions in 23s rRNA.
• A functional peptide encoded in the Escherichia coli 23S rRNA.
• Functional interactions within 23S rRNA involving the peptidyltransferase center.
• Mutations in the GTPase Center of Escherichia coli 23S rRNA Indicate Release Factor 2-Interactive Sites