Bechhofer D H, Zen K H
Department of Biochemistry, Mount Sinai School of Medicine, New York, New York 10029.
J Bacteriol. 1989 Nov;171(11):5803-11. doi: 10.1128/jb.171.11.5803-5811.1989.
In Bacillus subtilis, the ermC gene encodes an mRNA that is unusually stable (40-min half-life) in the presence of erythromycin, an inducer of ermC gene expression. A requirement for this induced mRNA stability is a ribosome stalled in the ermC leader region. This property of ermC mRNA was used to study the decay of mRNA in B. subtilis. Using constructs in which the ribosome stall site was internal rather than at the 5' end of the message, we show that ribosome stalling provides stability to sequences downstream but not upstream of the ribosome stall site. Our results indicate that ermC mRNA is degraded by a ribonucleolytic activity that begins at the 5' end and degrades the message in a 5'-to-3' direction.
在枯草芽孢杆菌中，ermC基因编码一种mRNA，在红霉素（ermC基因表达的诱导剂）存在的情况下，这种mRNA异常稳定（半衰期为40分钟）。诱导的mRNA稳定性的一个必要条件是核糖体停滞在ermC前导区域。ermC mRNA的这一特性被用于研究枯草芽孢杆菌中mRNA的降解。使用核糖体停滞位点位于内部而非位于mRNA 5'端的构建体，我们表明核糖体停滞为核糖体停滞位点下游而非上游的序列提供稳定性。我们的结果表明，ermC mRNA通过一种核糖核酸酶活性被降解，该活性从5'端开始并以5'到3'的方向降解该mRNA。
