Sterckx Yann G J, Garcia-Pino Abel, Haesaerts Sarah, Jové Thomas, Geerts Lieselotte, Sakellaris Viktor, Van Melderen Laurence, Loris Remy
Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel, Belgium.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2012 Jun 1;68(Pt 6):724-9. doi: 10.1107/S1744309112015230. Epub 2012 May 25.
Escherichia coli O157 paaR2-paaA2-parE2 constitutes a unique three-component toxin-antitoxin (TA) module encoding a toxin (ParE2) related to the classic parDE family but with an unrelated antitoxin called PaaA2. The complex between PaaA2 and ParE2 was purified and characterized by analytical gel filtration, dynamic light scattering and small-angle X-ray scattering. It consists of a particle with a radius of gyration of 3.95 nm and is likely to form a heterododecamer. Crystals of the ParE2-PaaA2 complex diffract to 3.8 Å resolution and belong to space group P3(1)21 or P3(2)21, with unit-cell parameters a = b = 142.9, c = 87.5 Å. The asymmetric unit is consistent with a particle of around 125 kDa, which is compatible with the solution data. Therefore, the ParE2-PaaA2 complex is the largest toxin-antitoxin complex identified to date and its quaternary arrangement is likely to be of biological significance.
大肠杆菌O157的paaR2 - paaA2 - parE2构成了一个独特的三组分毒素 - 抗毒素（TA）模块，该模块编码一种与经典parDE家族相关的毒素（ParE2），但其抗毒素名为PaaA2，与经典抗毒素无关。通过分析凝胶过滤、动态光散射和小角X射线散射对PaaA2和ParE2之间的复合物进行了纯化和表征。它由一个回转半径为3.95 nm的粒子组成，可能形成一个异十二聚体。ParE2 - PaaA2复合物的晶体衍射分辨率达到3.8 Å，属于空间群P3(1)21或P3(2)21，晶胞参数a = b = 142.9，c = 87.5 Å。不对称单元与一个约125 kDa的粒子一致，这与溶液数据相符。因此，ParE2 - PaaA2复合物是迄今为止鉴定出的最大的毒素 - 抗毒素复合物，其四级结构可能具有生物学意义。
