A Bacillus subtilis regulatory gene product for genetic competence and sporulation resembles sensor protein members of the bacterial two-component signal-transduction systems.
A Bacillus subtilis regulatory gene product for genetic competence and sporulation resembles sensor protein members of the bacterial two-component signal-transduction systems.
复制标题
DOI：
10.1101/gad.4.5.860
复制
发表时间：
1990-05
影响因子：
10.5
通讯作者：
Y. Weinrauch;R. Penchev;E. Dubnau;I. Smith;D. Dubnau
中科院分区：
文献类型：
--
作者：
Y. Weinrauch;R. Penchev;E. Dubnau;I. Smith;D. Dubnau
在先前鉴定的基因 comA 的上游立即鉴定出遗传能力所需的枯草芽孢杆菌基因。已发现 comA 基因产物表现出与所谓的信号转导蛋白效应子类相似的氨基酸序列。对名为 comP 的新决定簇进行 DNA 测序表明，预测的 ComP 蛋白的羧基末端结构域的氨基酸序列与细菌双组分信号转导系统的几个传感器成员的氨基酸序列相似。预测的氨基末端结构域包含几个疏水片段，假定是跨膜的。体外衍生的 comP 破坏对所有测试的晚期能力基因（包括 comG、comC、comD 和 comE）的表达上位，但对早期基因 comB 的表达不上位。尽管 comA 有自己的启动子，但 comA 的一些转录（尤其是在生长后期）是通过 comP 序列的通读发生的。在下游 comA 决定簇上注意到 comP 破坏的大约双重上位效应，这可能是由于从 comP 到 comA 的通读转录的中断。 comA 的过表达完全恢复了 comP 突变体的能力，提供了 ComA 在 ComP 之后起作用的证据，并且与后一种蛋白质可能通过磷酸化激活前者的作用一致。 ComP 可能参与传输有关培养基营养状况的信息，特别是含氮和含碳营养物的存在。 ComP 还被证明在孢子形成中发挥作用，至少部分可与另一种假定的传感器蛋白 SpoIIJ 互换。
A Bacillus subtilis gene, required for genetic competence, was identified immediately upstream from the previously characterized gene comA. The comA gene product has been found to exhibit amino acid sequence similarity to the so-called effector class of signal-transduction proteins. DNA sequencing of the new determinant, named comP, revealed that the carboxy-terminal domain of the predicted ComP protein is similar in amino acid sequence to that of several sensor members of the bacterial two-component signal-transduction systems. The predicted amino-terminal domain contains several hydrophobic segments, postulated to be membrane-spanning. In vitro-derived comP disruptions are epistatic on the expression of all late competence genes tested, including comG, comC, comD, and comE, but not on expression of the early gene comB. Although comA has its own promoter, some transcription of comA, especially later in growth, occurs via readthrough from comP sequences. A roughly twofold epistatic effect of a comP disruption was noted on the downstream comA determinant, possibly due to interruption of readthrough transcription from comP to comA. Overexpression of comA fully restored competence to a comP mutant, providing evidence that ComA acts after ComP, and consistent with a role for the latter protein in activation of the former, possibly by phosphorylation. ComP probably is involved in transmitting information concerning the nutritional status of the medium, particularly the presence of nitrogen- and carbon-containing nutrients. ComP was also shown to play a role in sporulation, at least partly interchangeable with that of SpoIIJ, another putative sensor protein.