Mudd E A, Higgins C F
Imperial Cancer Research Fund Laboratories, University of Oxford, John Radcliffe Hospital, UK.
Mol Microbiol. 1993 Aug;9(3):557-68. doi: 10.1111/j.1365-2958.1993.tb01716.x.
Mutations in the Escherichia coli rne (ams) gene have a general effect on the rate of mRNA decay in vivo. Using antibodies we have shown that the product of the rne gene is a polypeptide of relative mobility 180 kDa. However, proteolytic fragments as small as 70 kDa, which can arise during purification, also exhibit RNase E activity. In vitro studies demonstrate that the rne gene product, RNase E, is an endoribonuclease that cleaves mRNA at specific sites. RNase E cleaves rne mRNA and autoregulates the expression of the rne gene. In addition we demonstrate RNase E-dependent endonucleolytic cleavage of ompA mRNA, at a site known to be rate-determining for degradation and reported to be cleaved by RNase K. Our data are consistent with RNase K being a proteolytic fragment of RNase E.
大肠杆菌rne（ams）基因的突变对体内mRNA的衰减速率具有普遍影响。我们利用抗体证明，rne基因的产物是一种相对迁移率为180 kDa的多肽。然而，在纯化过程中产生的小至70 kDa的蛋白水解片段也表现出RNase E活性。体外研究表明，rne基因产物RNase E是一种内切核糖核酸酶，可在特定位点切割mRNA。RNase E切割rne mRNA并自动调节rne基因的表达。此外，我们证明了ompA mRNA在一个已知为降解速率决定位点且据报道可被RNase K切割的位点发生了依赖于RNase E的内切核酸酶切割。我们的数据与RNase K是RNase E的蛋白水解片段这一观点一致。
