Loiseau Laurent, Gerez Catherine, Bekker Martijn, Ollagnier-de Choudens Sandrine, Py Béatrice, Sanakis Yannis, Teixeira de Mattos Joost, Fontecave Marc, Barras Frédéric
Unité Propre de Recherche 9043, Laboratoire de Chimie Bactérienne, Centre National de la Recherche Scientifique, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
Proc Natl Acad Sci U S A. 2007 Aug 21;104(34):13626-31. doi: 10.1073/pnas.0705829104. Epub 2007 Aug 14.
Understanding the biogenesis of iron-sulfur (Fe-S) proteins is relevant to many fields, including bioenergetics, gene regulation, and cancer research. Several multiprotein complexes assisting Fe-S assembly have been identified in both prokaryotes and eukaryotes. Here, we identify in Escherichia coli an A-type Fe-S protein that we named ErpA. Remarkably, erpA was found essential for growth of E. coli in the presence of oxygen or alternative electron acceptors. It was concluded that isoprenoid biosynthesis was impaired by the erpA mutation. First, the eukaryotic mevalonate-dependent pathway for biosynthesis of isopentenyl diphosphate restored the respiratory defects of an erpA mutant. Second, the erpA mutant contained a greatly reduced amount of ubiquinone and menaquinone. Third, ErpA bound Fe-S clusters and transferred them to apo-IspG, a protein catalyzing isopentenyl diphosphate biosynthesis in E. coli. Surprisingly, the erpA gene maps at a distance from any other Fe-S biogenesis-related gene. ErpA is an A-type Fe-S protein that is characterized by an essential role in cellular metabolism.
了解铁硫（Fe-S）蛋白的生物合成与许多领域相关，包括生物能量学、基因调控和癌症研究。在原核生物和真核生物中都已鉴定出几种协助Fe-S组装的多蛋白复合物。在这里，我们在大肠杆菌中鉴定出一种A型Fe-S蛋白，我们将其命名为ErpA。值得注意的是，发现erpA对于大肠杆菌在有氧或替代电子受体存在下的生长至关重要。得出的结论是，类异戊二烯生物合成因erpA突变而受损。首先，用于生物合成异戊烯基二磷酸的真核甲羟戊酸依赖性途径恢复了erpA突变体的呼吸缺陷。其次，erpA突变体中泛醌和甲基萘醌的含量大大降低。第三，ErpA结合Fe-S簇并将它们转移到脱辅基IspG，IspG是一种在大肠杆菌中催化异戊烯基二磷酸生物合成的蛋白质。令人惊讶的是，erpA基因与任何其他与Fe-S生物合成相关的基因相距一定距离。ErpA是一种A型Fe-S蛋白，其特点是在细胞代谢中起重要作用。
