Abstract：
The recombination directionality factors from Mesorhizobium spp. (RdfS) are involved in regulating the excision and transfer of integrative and conjugative elements. Here, solution small-angle X-ray scattering, and crystallization and preliminary structure solution of RdfS from Mesorhizobium japonicum R7A are presented. RdfS crystallizes in space group P212121, with evidence of eightfold rotational crystallographic/noncrystallographic symmetry. Initial structure determination by molecular replacement using ab initio models yielded a partial model (three molecules), which was completed after manual inspection revealed unmodelled electron density. The finalized crystal structure of RdfS reveals a head-to-tail polymer forming left-handed superhelices with large solvent channels. Additionally, RdfS has significant disorder in the C-terminal region of the protein, which is supported by the solution scattering data and the crystal structure. The steps taken to finalize structure determination, as well as the scattering and crystallographic characteristics of RdfS, are discussed.
摘要：
中根瘤菌的重组方向性因子。（RdfS）参与调节整合和共轭元件的切除和转移。这里,溶液小角X射线散射，并给出了日本根瘤菌R7A中RdfS的结晶和初步结构溶液。RdfS在空间群P212121中结晶，具有八倍旋转晶体学/非晶体学对称性的证据。通过使用从头算模型进行分子置换的初始结构确定产生了部分模型（三个分子），这是在手动检查显示未建模的电子密度后完成的。RdfS的最终晶体结构揭示了头对尾聚合物，形成具有大溶剂通道的左手超螺旋。此外,RdfS在蛋白质的C末端区域有明显的紊乱，这得到了溶液散射数据和晶体结构的支持。为最终确定结构而采取的步骤，以及Rdfs的散射和晶体学特性，正在讨论。
