Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram-Positif, CNRS URA 2172, F-75015 Paris, France.
Microbiology (Reading). 2011 Aug;157(Pt 8):2226-2234. doi: 10.1099/mic.0.048454-0. Epub 2011 Jun 2.
ADEP, a molecule of the acyl depsipeptide family, has an antibiotic activity with a unique mode of action. ADEP binding to the ubiquitous protease ClpP alters the structure of the enzyme. Access of protein to the ClpP proteolytic chamber is therefore facilitated and its cohort regulatory ATPases (ClpA, ClpC, ClpX) are not required. The consequent uncontrolled protein degradation in the cell appears to kill the ADEP-treated bacteria. ADEP is produced by Streptomyces hawaiiensis. Most sequenced genomes of Streptomyces have five clpP genes, organized as two distinct bicistronic operons, clpP1clpP2 and clpP3clpP4, and a single clpP5 gene. We investigated whether the different Clp proteases are all sensitive to ADEP. We report that ClpP1 is a target of ADEP whereas ClpP3 is largely insensitive. In wild-type Streptomyces lividans, clpP3clpP4 expression is constitutively repressed and the reason for the maintenance of this operon in Streptomyces has been elusive. ClpP activity is indispensable for survival of actinomycetes; we therefore tested whether the clpP3clpP4 operon, encoding an ADEP-insensitive Clp protease, contributes to a mechanism of ADEP resistance by target substitution. We report that in S. lividans, inactivation of ClpP1ClpP2 production or protease activity is indeed a mode of resistance to ADEP although it is neither the only nor the most frequent mode of resistance. The ABC transporter SclAB (orthologous to the Streptomyces coelicolor multidrug resistance pump SCO4959-SCO4960) is also able to confer ADEP resistance, and analysis of strains with sclAB deletions indicates that there are also other mechanisms of ADEP resistance.
ADEP 是酰基辅肽类家族的一个分子，具有独特的作用模式的抗生素活性。ADEP 与普遍存在的蛋白酶 ClpP 结合会改变酶的结构。因此，蛋白质更容易进入 ClpP 的蛋白水解腔室，并且不需要其共同的调节 ATP 酶（ClpA、ClpC、ClpX）。细胞中不受控制的蛋白质降解似乎导致 ADEP 处理的细菌死亡。ADEP 由链霉菌属产生。大多数链霉菌的测序基因组有五个 clpP 基因，组织为两个不同的双顺反子操纵子 clpP1clpP2 和 clpP3clpP4，以及一个单独的 clpP5 基因。我们研究了不同的 Clp 蛋白酶是否都对 ADEP 敏感。我们报告说 ClpP1 是 ADEP 的靶标，而 ClpP3 则基本不敏感。在野生型链霉菌中，clpP3clpP4 的表达被组成型抑制，而链霉菌中维持该操纵子的原因一直难以捉摸。ClpP 活性对放线菌的生存是必不可少的；因此，我们测试了编码对 ADEP 不敏感的 Clp 蛋白酶的 clpP3clpP4 操纵子是否通过靶标替换有助于 ADEP 抗性的机制。我们报告说，在 S. lividans 中，失活 ClpP1ClpP2 的产生或蛋白酶活性确实是对 ADEP 的一种抗性模式，尽管它不是唯一的或最常见的抗性模式。ABC 转运蛋白 SclAB（与链霉菌协同素多药耐药泵 SCO4959-SCO4960 同源）也能够赋予 ADEP 抗性，并且对 sclAB 缺失菌株的分析表明，还存在其他 ADEP 抗性机制。
