Cairrão Fátima, Arraiano Cecília Maria
Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apt. 127, 2781-901 Oeiras, Portugal.
Biochem Biophys Res Commun. 2006 May 12;343(3):731-7. doi: 10.1016/j.bbrc.2006.03.040. Epub 2006 Mar 15.
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.
核糖核酸酶R是一种重要的外切核糖核酸酶，参与RNA的成熟和降解过程。核糖核酸酶R与同一操纵子中的其他基因共同转录。在本报告中，我们表明在生理条件下，这些共转录本的成熟以及核糖核酸酶R的水平主要依赖于核糖核酸内切酶核糖核酸酶E。全长核糖核酸酶E的存在对于rnr操纵子转录本成熟过程中产生的中间产物的降解是必需的。核糖核酸酶G和核糖核酸酶III似乎在rnr转录本的加工过程中不发挥主要作用。然而，rnr突变体中中间转录本的积累表明核糖核酸酶G可能在核糖核酸酶E已切割的转录本的降解中起作用。这些结果表明，其他核糖核酸酶可以在核糖核酸酶R表达的控制中作为额外的调控水平发挥作用。
