SEQUENCE AND TRANSCRIPTIONAL PATTERN OF THE ESSENTIAL ESCHERICHIA-COLI SECE-NUSG OPERON
SEQUENCE AND TRANSCRIPTIONAL PATTERN OF THE ESSENTIAL ESCHERICHIA-COLI SECE-NUSG OPERON
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DOI：
10.1128/jb.172.3.1621-1627.1990
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发表时间：
1990-03-01
影响因子：
3.2
通讯作者：
DENNIS, PP
中科院分区：
文献类型：
--
作者：
DOWNING, WL;SULLIVAN, SL;DENNIS, PP
两个基因，secE和nusG，位于tufB和核糖体蛋白rplKAJL操纵子之间的rif区域在90分钟的大肠杆菌染色体上，已被测序和表征。secE基因编码一种127个氨基酸长的多肽，它是蛋白质输出所必需的完整膜蛋白（P. J. Schatz，PD.里格斯，A。Jacq，M. J. Fath和J. Beckwith，Genes Dev. 3：1035-1044，1989）。nusG基因编码一个181个氨基酸长的多肽，并参与转录抗终止。nusG的蛋白质产物对于细菌存活力是必需的。secE-nusG基因是共转录的，转录物起始于PEG启动子并终止于rplK启动子区域中的Rho非依赖性终止子。大多数转录物在5“非翻译前导区的多个位点被RNase III加工，并且可能还被第二种未鉴定的核酸酶加工。转录处理在secE和nusG调节中的作用尚未确定。蛋白质输出因子和转录因子的并列和共调节引起了关于这两个过程之间的功能连接的问题。
Two genes, secE and nusG, situated between the tufB and ribosomal protein rplKAJL operons in the rif region at 90 min on the Escherichia coli chromosome, have been sequenced and characterized. The secE gene encodes a 127-amino-acid-long polypeptide, which is an integral membrane protein essential for protein export (P. J. Schatz, P. D. Riggs, A. Jacq, M. J. Fath, and J. Beckwith, Genes Dev. 3:1035-1044, 1989). The nusG gene encodes a 181-amino-acid-long polypeptide and is involved in transcription antitermination. The protein product of nusG is essential for bacterial viability. The secE-nusG genes are cotranscribed, with transcripts initiated at the PEG promoter and terminated at the Rho-independent terminator in the region of the rplK promoter. The majority of transcripts are processed at a number of sites in the 5'' untranslated leader region by RNase III and are possibly also processed by a second unidentified nuclease. The role of transcript processing in the regulation of secE and nusG has not yet been established. The juxtaposition and coregulation of a protein export factor and a transcriptional factor raise questions concerning a functional connection between the two processes.