Derré I, Rapoport G, Devine K, Rose M, Msadek T
Unité de Biochimie Microbienne, URA 1300 du Centre National de la Recherche Scientifique, Institut Pasteur, 25, rue du Docteur Roux, 75724 Paris Cedex 15, France.
Mol Microbiol. 1999 May;32(3):581-93. doi: 10.1046/j.1365-2958.1999.01374.x.
Clp ATPases, which include the ubiquitous HSP100 family, are classified according to their structural features and sequence similarities. During the course of the Bacillus subtilis genome sequencing project, we identified a gene encoding a new member of the HSP100 family. We designated this protein ClpE, as it is the prototype of a novel subfamily among the Clp ATPases, and have identified homologues in several bacteria, including Listeria monocytogenes, Enterococcus faecalis, Streptococcus pyogenes, Streptococcus pneumoniae, Lactobacillus sakei and Clostridium acetobutylicum. A unique feature of these Hsp100-type Clp ATPases is their amino-terminal zinc finger motif. Unlike the other class III genes of B. subtilis (clpC and clpP ), clpE does not appear to be required for stress tolerance. Transcriptional analysis revealed two sigmaA-type promoters, expression from which was shown to be inducible by heat shock and puromycin treatment. Investigation of the regulatory mechanism controlling clpE expression indicates that this gene is controlled by CtsR and is thus a member of the class III heat shock genes of B. subtilis. CtsR negatively regulates clpE expression by binding to the promoter region, in which five CtsR binding sites were identified through DNase I footprinting and sequence analysis.
Clp ATP酶包括普遍存在的HSP100家族，根据其结构特征和序列相似性进行分类。在枯草芽孢杆菌基因组测序项目过程中，我们鉴定出一个编码HSP100家族新成员的基因。我们将该蛋白命名为ClpE，因为它是Clp ATP酶中一个新亚家族的原型，并且在几种细菌中鉴定出了同源物，包括单核细胞增生李斯特菌、粪肠球菌、化脓性链球菌、肺炎链球菌、清酒乳杆菌和丙酮丁醇梭菌。这些Hsp100型Clp ATP酶的一个独特特征是其氨基末端锌指基序。与枯草芽孢杆菌的其他III类基因（clpC和clpP）不同，clpE似乎不是应激耐受所必需的。转录分析揭示了两个sigmaA型启动子，热休克和嘌呤霉素处理可诱导其表达。对控制clpE表达的调控机制的研究表明，该基因受CtsR调控，因此是枯草芽孢杆菌III类热休克基因家族的成员。CtsR通过与启动子区域结合来负调控clpE的表达，通过DNase I足迹分析和序列分析在该区域鉴定出了五个CtsR结合位点。
