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R A Garrett

Publications and source records attributed to R A Garrett.

168 records · Page 10Linked to original sources
PubMedDate not supplied

Binding sites of the antibiotics pactamycin and celesticetin on ribosomal RNAs.

The binding sites of the antibiotics pactamycin and celesticetin on the rRNAs of Escherichia coli ribosomes were investigated by a chemical footprinting procedure. Pactamycin protected residues G-693 and C-795 in 16S RNA which are located in an important functional region of the 30S subunit participating in initiation complex formation and ribosomal subunit interaction. Celesticetin altered the reactivities of 5 residues A-2058, A-2059, A-2062, A-2451 and G-2505 within the central loop of domain V of 23S RNA which has been implicated in peptidyltransferase activity. Inferences are drawn concerning the mode of action of the antibiotics.

Anti-Bacterial Agents↗
PubMedDate not supplied

Antibiotic inhibition of the movement of tRNA substrates through a peptidyl transferase cavity.

The present review attempts to deal with movement of tRNA substrates through the peptidyl transferase centre on the large ribosomal subunit and to explain how this movement is interrupted by antibiotics. It builds on the concept of hybrid tRNA states forming on ribosomes and on the observed movement of the 5' end of P-site-bound tRNA relative to the ribosome that occurs on peptide bond formation. The 3' ends of the tRNAs enter, and move through, a catalytic cavity where antibiotics are considered to act by at least three primary mechanisms: (i) they interfere with the entry of the aminoacyl moiety into the catalytic cavity before peptide bond formation; (ii) they inhibit movement of the nascent peptide along the peptide channel, a process that may generally involve destabilization of the peptidyl tRNA, and (iii) they prevent movement of the newly deacylated tRNA between the P/P and hybrid P/E sites on peptide bond formation.

Anti-Bacterial Agents↗