MecB of Bacillus subtilis, a member of the ClpC ATPase family, is a pleiotropic regulator controlling competence gene expression and growth at high temperature.
MecB of Bacillus subtilis, a member of the ClpC ATPase family, is a pleiotropic regulator controlling competence gene expression and growth at high temperature.
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枯草芽孢杆菌的 MecB 是 ClpC ATPase 家族的成员，是一种多效性调节因子，控制高温下能力基因的表达和生长。
DOI：
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发表时间：
1994
影响因子：
11.1
通讯作者：
Georges Rapoport
中科院分区：
文献类型：
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作者：
T. Msadek;Frank Kunst;Georges Rapoport
枯草芽孢杆菌DegS-DegU组氨酸激酶应答调节因子对控制编码降解酶如果聚糖蔗糖酶（sacB）的基因和涉及遗传感受态的基因的表达。mecA和mecB突变先前被分离为允许感受态基因在复杂培养基中表达。我们已经表明，mec突变也导致sacB的过表达，绕过DegS-DegU的要求。这种表达被证明是完全依赖于ComK，感受态基因表达的正调控因子。克隆了mecB基因并测定了其核苷酸序列。预测的MecB蛋白在其整个长度上与ATP酶的ClpC家族的成员显示出非常高的相似性（60%同一性）。Mec B对B的生长至关重要。枯草芽孢杆菌在高温下。MecB还作为ComK合成的负调节剂，从而阻止晚期感受态基因表达。我们认为，在这些条件下，MecB可能与MecA相互作用，以螯合或以其他方式抑制ComK。为了响应未知信号，活性ComK将通过正反馈回路积累，导致允许DNA摄取的感受态基因的表达。
The Bacillus subtilis DegS-DegU histidine kinase-response regulator pair controls the expression of genes encoding degradative enzymes such as levansucrase (sacB) and of genes involved in genetic competence. The mecA and mecB mutations were previously isolated as allowing competence gene expression in complex media. We have shown that the mec mutations also lead to overexpression of sacB, bypassing the DegS-DegU requirement. This expression was shown to be entirely dependent upon ComK, a positive regulator of competence gene expression. The mecB gene was cloned and its nucleotide sequence was determined. The predicted MecB protein show very high similarity over its entire length with members of the ClpC family of ATPases (60% identity). MecB is essential for growth of B. subtilis at high temperature. MecB also acts as a negative regulator of ComK synthesis, thus preventing late competence gene expression. We suggest that under these conditions MecB may interact with MecA to sequester or otherwise inactivate ComK. In response to an unknown signal, active ComK would accumulate through a positive feedback loop, leading to expression of competence genes allowing DNA uptake.