Conjugative transfer of Enterococcus faecalis plasmid pAD1: nucleotide sequence and transcriptional fusion analysis of a region involved in positive regulation.
Conjugative transfer of Enterococcus faecalis plasmid pAD1: nucleotide sequence and transcriptional fusion analysis of a region involved in positive regulation.
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粪肠球菌质粒 pAD1 的接合转移：参与正调节的区域的核苷酸序列和转录融合分析。
DOI：
10.1128/jb.174.10.3152-3160.1992
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发表时间：
1992
影响因子：
3.2
通讯作者：
Clewell,DB
中科院分区：
文献类型：
--
作者：
Pontius,LT;Clewell,DB
粪肠球菌质粒 pAD1 响应 cAD1（潜在细菌受体释放的一种肽性信息素）进行接合转移。 pAD1转移的调节涉及许多质粒编码的决定簇：iad，它决定肽竞争性抑制剂iAD1；信号传感和转换元件；以及负调节器和正调节器。据信，信息素反应的关键正调节因子是在质粒 E 区的片段内编码的。在这项研究中，我们分析了 E 区内的核苷酸序列和转录。鉴定出一个开放阅读框，命名为 traE1；其推断蛋白质由118个氨基酸组成。 traE1 的插入突变导致质粒转移能力完全丧失。对产生转录 lacZ 融合的 Tn917-lac 插入的分析表明，traE1 仅在 cAD1 诱导条件下转录。对该区域内其他 lacZ 融合体的分析提供了对此处报道的核苷酸序列内部和周围潜在调节信号的作用的一些见解。似乎涉及某些关键转录终止序列的通读的调节作用似乎很明显。
The Enterococcus faecalis plasmid pAD1 undergoes conjugative transfer in response to cAD1, a peptide sex pheromone emitted by potential bacterial recipients. Regulation of pAD1 transfer involves a number of plasmid-encoded determinants:iad, which determines a peptide-competitive inhibitor iAD1; signal sensing and transducing elements; and negative and positive regulators. The key positive regulator(s) of the pheromone response is believed to be encoded within a segment designated the E region of the plasmid. In this study, we analyzed the nucleotide sequence and transcription within the E region. An open reading frame designated traE1 was identified; its inferred protein consists of 118 amino acids. Insertional mutagenesis of traE1 resulted in a complete loss in plasmid transfer capability. Analysis of Tn917-lac insertions giving rise to transcriptional lacZ fusions showed that traE1 is transcribed only under cAD1 inducing conditions. Analysis of additional lacZ fusions within the region provided some insight into the roles of potential regulatory signals within and around the nucleotide sequences reported here. A regulatory role appearing to involve read-through of certain key transcription termination sequences seemed evident.