title: Attenuation and processing of RNA from the rplJL--rpoBC transcription unit of Escherichia coli.
abstract: Attenuation and processing of the mRNA from the ribosomal protein-RNA polymerase operon rplJL--rpoBC have been demonstrated by the analysis of nuclease SI-resistant RNA . DNA hybrids. These hybrids were formed between RNA produced in vivo and specific DNA restriction fragments which span the rplL--rpoB intercistronic region. The 3' end of the predominant attenuated RNA lies 69 nucleotides beyond the end of the rplL gene following sequence features that are similar to those of other known attenuators. The nonattenuated transcript is normally cleaved in the intercistronic region. However, in an RNase III mutant strain, the hybrids corresponding to the cleaved nonattenuated mRNAs disappear and the expected full-sized hybrid is seen. We have localized the cleavage to an area of possible secondary structure in the transcript approximately 200 nucleotides beyond the end of the rplL gene. This demontrates RNase III processing of Escherichia coli mRNA. The methods used in this study permit the examination of specific ends of large and complex polycistronic mRNAs. Such experiments should help in understanding how posttranscriptional events influence gene expression.
mesh_terms: D004269:DNA, Bacterial / Q000378:metabolism; D004274:DNA, Recombinant / Q000378:metabolism; D004720:Endonucleases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005796:Genes; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D009876:Operon; D010957:Plasmids; D014176:Protein Biosynthesis; D012318:RNA Polymerase I / Q000235:genetics; D012329:RNA, Bacterial / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D043244:Ribonuclease III; D012260:Ribonucleases / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D004269:DNA, Bacterial; D004274:DNA, Recombinant; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012269:Ribosomal Proteins; D012318:RNA Polymerase I; D004720:Endonucleases; D012260:Ribonucleases; D043244:Ribonuclease III; C468366:ribonuclease III, E coli