Chloramphenicol-induced translational activation of cat messenger RNA in vitro.
The expression of the chloramphenicol-inducible chloramphenicol acetyltransferase gene (cat) of the staphylococcal plasmid pUB112 is regulated at the post-transcriptional level. Previous in vivo analyses suggested that the antibiotic stalls ribosomes that are translating a regulatory leader peptide, and that a stalled ribosome activates the ribosome binding site of the acetyltransferase encoding sequence by opening an attenuating leader mRNA hairpin structure. To test this model, we used a Bacillus subtilis S-30 extract for an in vitro translation system and in vitro synthesized cat in RNAs. We showed that the leader portion of the cat transcript acts as a translational attenuator of cat gene expression in absence of chloramphenicol. The drug stimulates acetyltransferase synthesis by a leader mRNA-dependent activation of translation of the cat message. By using 5' end-labeled transcripts and employing the endogenous RNase activity of the S-30 extract we demonstrated that this activation is due to an antibiotic-induced stalling of a ribosome on cat leader mRNA.
Dick
T
T
Molekulare Genetik der Universität, Heidelberg, Federal Republic of Germany.
Matzura
H
H
D001412:Bacillus subtilis / Q000235:genetics*; D001483:Base Sequence; D002701:Chloramphenicol / Q000494:pharmacology*; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D014158:Transcription, Genetic
D012333:RNA, Messenger; D002701:Chloramphenicol; D015500:Chloramphenicol O-Acetyltransferase