Initiation of decay of Bacillus subtilis trp leader RNA
Initiation of decay of Bacillus subtilis trp leader RNA
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DOI：
10.1074/jbc.m702747200
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发表时间：
2007-07-13
影响因子：
4.8
通讯作者：
Bechhofer, David H.
中科院分区：
文献类型：
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作者：
Deikus, Gintaras;Bechhofer, David H.
枯草芽孢杆菌trp操纵子前导区的转录终止受11-mer TRAP复合物与新生trp RNA结合的调节，这导致终止子结构的形成。trp前导RNA的快速衰变是释放TRAP复合物并维持足够的游离TRAP供应所需的，由多核苷酸磷酸化酶（PNPase）介导。使用纯化的B。枯草杆菌PNTR的结果表明，当TRAP存在时，PNTR结合trp前导RNA的3'末端和PNTR从3'末端消化trp前导RNA是无效的。这些结果表明，启动的trp前导RNA可能开始开始与内切酶切割上游的转录终止子结构。在体内观察到这种切割。在切割位点的核苷酸突变废除加工，并导致色氨酸前导RNA半衰期增加4倍。这是第一次绘制天然B上的衰变起始核酸内切酶切割位点。枯草RNA。
Transcription termination in the leader region of the Bacillus subtilis trp operon is regulated by binding of the 11-mer TRAP complex to nascent trp RNA, which results in formation of a terminator structure. Rapid decay of trp leader RNA, which is required to release the TRAP complex and maintain a sufficient supply of free TRAP, is mediated by polynucleotide phosphorylase (PNPase). Using purified B. subtilis PNPase, we showed that, when TRAP was present, PNPase binding to the 3' end of trp leader RNA and PNPase digestion of trp leader RNA from the 3' end were inefficient. These results suggested that initiation of trp leader RNA may begin with an endonuclease cleavage upstream of the transcription terminator structure. Such cleavage was observed in vivo. Mutagenesis of nucleotides at the cleavage site abolished processing and resulted in a 4-fold increase in trp leader RNA half-life. This is the first mapping of a decay-initiating endonuclease cleavage site on a native B. subtilis RNA.