Giedroc David P
Department of Chemistry, Indiana University, Bloomington, IN 47405-7002, USA.
Mol Microbiol. 2009 Jul;73(1):1-4. doi: 10.1111/j.1365-2958.2009.06752.x. Epub 2009 Jun 8.
Microorganisms have evolved an impressive array of mechanisms to adapt to stress induced by reactive oxygen species (ROS) of virtually any kind. One such regulator is Bacillus subtilis PerR, a member of the ubiquitous Fur (Ferric uptake regulator) family of metalloregulatory repressors, which senses hydrogen peroxide. In this issue of Molecular Microbiology, Duarte, Latour and colleagues report the structure of the Mn(II)-bound form of PerR, a first for the Fe/Mn-selective members of the Fur family. The structure reveals how a regulatory metal drives a quaternary structural switch that allosterically activates the PerR dimer to bind its DNA operator, while also providing detailed insight into the mechanism of metal-catalysed ligand oxidation and transcriptional derepression that uniquely characterizes PerR.
微生物已经进化出一系列令人印象深刻的机制来适应几乎任何种类的活性氧（ROS）所诱导的应激。其中一种调节因子是枯草芽孢杆菌的PerR，它是普遍存在的金属调节阻遏物Fur（铁摄取调节因子）家族的成员之一，可感知过氧化氢。在本期《分子微生物学》中，杜阿尔特、拉图尔及其同事报道了结合锰（II）形式的PerR的结构，这是Fur家族中Fe/Mn选择性成员的首个此类结构。该结构揭示了一种调节金属如何驱动四级结构转换，从而变构激活PerR二聚体以结合其DNA操纵子，同时还深入详细地阐明了金属催化的配体氧化和转录去抑制机制，这是PerR独有的特征。
