Jacquamet L, Traoré D A K, Ferrer J-L, Proux O, Testemale D, Hazemann J-L, Nazarenko E, El Ghazouani A, Caux-Thang C, Duarte V, Latour J-M
Institut de Biologie Structurale CEA-CNRS-UJF, LCCP, GSY, 41 rue Jules Horowitz, 38027 Grenoble Cedex 1, France.
Mol Microbiol. 2009 Jul;73(1):20-31. doi: 10.1111/j.1365-2958.2009.06753.x. Epub 2009 Jun 8.
In Bacillus subtilis, the transcription factor PerR is an iron dependant sensor of H(2)O(2). The sensing mechanism relies on a selective metal catalysed oxidation of two histidine residues of the regulatory site. Here we present the first crystal structure of the active PerR protein in complex with a Mn(2+) ion. In addition, X-ray absorption spectroscopy experiments were performed to characterize the corresponding iron form of the protein. Both studies reveal a penta-coordinate arrangement of the regulatory site that involves three histidines and two aspartates. One of the histidine ligand belongs to the N-terminal domain. Binding of this residue to the regulatory metal allows the protein to adopt a caliper-like conformation suited to DNA binding. Since this histidine is conserved in all PerR and a vast majority of Fur proteins, it is likely that the allosteric switch induced by the regulatory metal is general for this family of metalloregulators.
在枯草芽孢杆菌中，转录因子PerR是一种对过氧化氢具有铁依赖性的传感器。其传感机制依赖于调节位点上两个组氨酸残基的选择性金属催化氧化。在此，我们展示了活性PerR蛋白与锰离子结合的首个晶体结构。此外，还进行了X射线吸收光谱实验以表征该蛋白相应的铁形式。两项研究均揭示了调节位点的五配位排列，该排列涉及三个组氨酸和两个天冬氨酸。其中一个组氨酸配体属于N端结构域。该残基与调节金属的结合使蛋白能够采取适合DNA结合的卡尺样构象。由于这个组氨酸在所有PerR以及绝大多数Fur蛋白中都保守存在，调节金属诱导的变构开关很可能在这个金属调节蛋白家族中是普遍存在的。
