DsrA RNA regulates translation of RpoS message by an anti-antisense mechanism, independent of its action as an antisilencer of transcription
DsrA RNA regulates translation of RpoS message by an anti-antisense mechanism, independent of its action as an antisilencer of transcription
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DOI：
10.1073/pnas.95.21.12462
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发表时间：
1998-10-13
影响因子：
11.1
通讯作者：
Gottesman, S
中科院分区：
文献类型：
--
作者：
Majdalani, N;Cunning, C;Gottesman, S
DSRA RNA通过克服类核相关H-NS蛋白的转录沉默来调节转录，并通过促进胁迫因子rpos的有效翻译来调节翻译。DSRA的这两种活性可以通过突变来分离：85个核苷酸RNA的三个茎环中的第一个是Rpos翻译所必需的，而不是抗H-NS作用所必需的，而第二个茎环是抗沉默所必需的，对Rpos翻译来说不是那么关键。第三个茎环作为转录终止子，可以被Trp转录终止子取代，而不会失去任何一个DSRA功能。DSRA的第一个茎环的序列与rpos信使RNA的上游前导部分是互补的，这表明DSRA与rpos信息的配对对翻译调控可能是重要的。RPOS前导序列的突变和DSRA的补偿性突变证实了这种预测的配对对于DSRA刺激RPOS翻译是必要的。我们认为DSRA配对通过充当反义RNA来刺激RPOS的翻译，将翻译起始区从顺式作用的反义RNA中解放出来，从而增加翻译。
DsrA RNA regulates both transcription, by overcoming transcriptional silencing by the nucleoid-associated H-NS protein, and translation, by promoting efficient translation of the stress a factor, RpoS. These two activities of DsrA can be separated by mutation: the first of three stem-loops of the 85 nucleotide RNA is necessary for RpoS translation but not for anti-H-NS action, while the second stem-loop is essential for antisilencing and less critical for RpoS translation. The third stem-loop, which behaves as a transcription terminator, can be substituted by the trp transcription terminator without loss of either DsrA function. The sequence of the first stem-loop of DsrA is complementary with the upstream leader portion of rpoS messenger RNA, suggesting that pairing of DsrA with the rpoS message might be important for translational regulation. Mutations in the Rpos leader and compensating mutations in DsrA confirm that this predicted pairing is necessary for DsrA stimulation of RpoS translation. We propose that DsrA pairing stimulates RpoS translation by acting as an anti-antisense RNA, freeing the translation initiation region from the cis-acting antisense RNA and allowing increased translation.