National Laboratory of Macromolecules, National Center of Protein Science-Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
National Laboratory of Macromolecules, National Center of Protein Science-Beijing, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
Biochem Biophys Res Commun. 2014 Jul 25;450(2):929-35. doi: 10.1016/j.bbrc.2014.06.053. Epub 2014 Jun 19.
YajR is an Escherichia coli transporter that belongs to the major facilitator superfamily. Unlike most MFS transporters, YajR contains a carboxyl terminal, cytosolic domain of 67 amino acid residues termed YAM domain. Although it is speculated that the function of this small soluble domain is to regulate the conformational change of the 12-helix transmembrane domain, its precise regulatory role remains unclear. Here, we report the crystal structure of the YAM domain at 1.07-Å resolution, along with its structure determined using nuclear magnetic resonance. Detailed analysis of the high resolution structure revealed a symmetrical dimer in which a belt of well-ordered poly-pentagonal water molecules is embedded. A mutagenesis experiment and a thermal stability assay were used to analyze the putative role of this dimerization in response to changes in halogen concentration.
YajR 是一种属于主要协助转运蛋白超家族的大肠杆菌转运蛋白。与大多数 MFS 转运蛋白不同，YajR 包含一个羧基末端、细胞质域的 67 个氨基酸残基，称为 YAM 结构域。虽然人们推测这个小可溶性结构域的功能是调节 12 个螺旋跨膜结构域的构象变化，但它的确切调节作用仍不清楚。在这里，我们报告了 YAM 结构域的晶体结构，分辨率为 1.07-Å，以及使用核磁共振确定的结构。对高分辨率结构的详细分析揭示了一个对称二聚体，其中嵌入了一个有序的多五边形水分子带。突变实验和热稳定性测定用于分析这种二聚化在响应卤素浓度变化中的可能作用。
