The role of endoribonucleases in the regulation of RNase R.
RNase R is an important exoribonuclease involved in the maturation and degradation of RNA. RNase R is co-transcribed with other genes in the same operon. In this report, we show that under physiological conditions maturation of these co-transcripts and the levels of RNase R are mainly dependent on the endoribonuclease RNase E. The presence of the full-length RNase E is necessary for the decay of intermediary products that arise from the maturation of transcripts from the rnr operon. RNase G and RNase III do not seem to have a primary role in the processing of the rnr transcripts. However, the accumulation of intermediary transcripts in an rng mutant suggests that RNase G may act in the degradation of the transcripts already cleaved by RNase E. These results demonstrated that other ribonucleases can act as an additional level of regulation in the control of the expression of RNase R.
Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apt. 127, 2781-901 Oeiras, Portugal. cairrao@cict.fr
Fátima
F
Cairrão
Cecília Maria
CM
Arraiano
D004722:Endoribonucleases / Q000502:physiology*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D005095:Exoribonucleases / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D009876:Operon; D012323:RNA Processing, Post-Transcriptional; D020871:RNA Stability; D012333:RNA, Messenger / Q000378:metabolism; D043244:Ribonuclease III / Q000502:physiology
D029968:Escherichia coli Proteins; D012333:RNA, Messenger; C489683:rnr protein, E coli; D004722:Endoribonucleases; D005095:Exoribonucleases; C081905:rng protein, E coli; D043244:Ribonuclease III; C468366:ribonuclease III, E coli; C022537:ribonuclease E