Crystallization and X-ray analysis of Borrelia burgdorferi beta-barrel assembly machinery Ay
Crystallization and X-ray analysis of Borrelia burgdorferi beta-barrel assembly machinery Ay
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伯氏疏螺旋体β-桶装配机械Ay的结晶和X射线分析
DOI：
10.1107/s2053230x20006196
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发表时间：
2020
影响因子：
0.9
通讯作者：
Qin Xiaochun
中科院分区：
文献类型：
--
作者：
Dong Shishang;Chu Hongguan;Wen Kangning;Yu Qianqian;Li Hui;Wang Changhui;Qin Xiaochun
线粒体、叶绿体和几种细菌具有执行许多基本生物学功能的外膜蛋白（OMPs）。β-桶状装配机械（BAM）复合物是导致莱姆病的伯氏疏螺旋体的omp之一，其BamA组分（BbBamA）包括一个c端β-桶状结构域和五个n端周围质多肽运输相关结构域，它们共同执行中心运输功能。本研究对BbBamA的三个n端POTRA结构域（BbBamA-POTRA P1-P3；残基30-273）的生成、结晶和x射线分析进行了研究。BbBamA-POTRA P1-P3晶体属于空间群P21，其单胞参数a = 45.353, b = 111.538, c = 64.376 Å， β = 99.913°。假设每个不对称单元存在两个分子，计算出Matthews系数为2.92 Å3 Da−1，相应的溶剂含量为57.9%。由于缺乏理想的同源性模型，许多使用分子替代（MR）解决BbBamA-POTRA P1-P3结构的尝试都失败了。为了解决该结构，目前正在进行硒代蛋氨酸衍生化的进一步试验。
Mitochondria, chloroplasts and several species of bacteria have outer membrane proteins (OMPs) that perform many essential biological functions. The β-barrel assembly machinery (BAM) complex is one of the OMPs of Borrelia burgdorferi, the pathogenic spirochete that causes Lyme disease, and its BamA component (BbBamA) includes a C-terminal β-barrel domain and five N-terminal periplasmic polypeptide-transport-associated (POTRA) domains, which together perform a central transport function. In the current work, the production, crystallization and X-ray analysis of the three N-terminal POTRA domains of BbBamA (BbBamA-POTRA P1–P3; residues 30–273) were carried out. The crystals of BbBamA-POTRA P1–P3 belonged to space group P21, with unit-cell parameters a = 45.353, b = 111.538, c = 64.376 Å, β = 99.913°. The Matthews coefficient was calculated to be 2.92 Å3 Da−1, assuming the presence of two molecules per asymmetric unit, and the corresponding solvent content was 57.9%. Owing to the absence of an ideal homology model, numerous attempts to solve the BbBamA-POTRA P1–P3 structure using molecular replacement (MR) failed. In order to solve the structure, further trials using selenomethionine derivatization are currently being carried out.