当前位置: X-MOL 学术BBA Bioenerg. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Unfolding pathway and intermolecular interactions of the cytochrome subunit in the bacterial photosynthetic reaction center.
Biochimica et Biophysica Acta (BBA) - Bioenergetics ( IF 3.4 ) Pub Date : 2020-04-17 , DOI: 10.1016/j.bbabio.2020.148204
Leanne C Miller 1 , Longsheng Zhao 2 , Daniel P Canniffe 3 , David Martin 4 , Lu-Ning Liu 5
Affiliation  

Precise folding of photosynthetic proteins and organization of multicomponent assemblies to form functional entities are fundamental to efficient photosynthetic electron transfer. The bacteriochlorophyll b-producing purple bacterium Blastochloris viridis possesses a simplified photosynthetic apparatus. The light-harvesting (LH) antenna complex surrounds the photosynthetic reaction center (RC) to form the RC-LH1 complex. A non-membranous tetraheme cytochrome (4Hcyt) subunit is anchored at the periplasmic surface of the RC, functioning as the electron donor to transfer electrons from mobile electron carriers to the RC. Here, we use atomic force microscopy (AFM) and single-molecule force spectroscopy (SMFS) to probe the long-range organization of the photosynthetic apparatus from Blc. viridis and the unfolding pathway of the 4Hcyt subunit in its native supramolecular assembly with its functional partners. AFM images reveal that the RC-LH1 complexes are densely organized in the photosynthetic membranes, with restricted lateral protein diffusion. Unfolding of the 4Hcyt subunit represents a multi-step process and the unfolding forces of the 4Hcyt α-helices are approximately 121 picoNewtons. Pulling of 4Hcyt could also result in the unfolding of the RC L subunit that binds with the N-terminus of 4Hcyt, suggesting strong interactions between RC subunits. This study provides new insights into the protein folding and interactions of photosynthetic multicomponent complexes, which are essential for their structural and functional integrity to conduct photosynthetic electron flow.

中文翻译:

细菌光合作用反应中心中细胞色素亚基的展开途径和分子间相互作用。

光合蛋白的精确折叠和多组分组装的组织以形成功能实体是有效的光合电子转移的基础。产生细菌叶绿素b的紫色细菌Blastochloris viridis具有简化的光合作用装置。光收集(LH)天线复合体围绕光合作用反应中心(RC)形成RC-LH1复合体。非膜四血红素细胞色素(4Hcyt)亚基锚定在RC的周质表面,用作电子供体,将电子从移动电子载体转移到RC。在这里,我们使用原子力显微镜(AFM)和单分子力谱(SMFS)来探测Blc光合作用仪器的远程组织。绿藻和其天然超分子装配中的4Hcyt亚基的展开途径及其功能伙伴。AFM图像显示RC-LH1复合物在光合膜中密集组织,横向蛋白质扩散受到限制。4Hcyt亚基的展开代表一个多步过程,而4Hcytα螺旋的展开力约为121皮牛顿。牵拉4Hcyt也可能导致与4Hcyt N末端结合的RC L亚基的解折叠,表明RC亚基之间存在强相互作用。这项研究为光合多组分复合物的蛋白质折叠和相互作用提供了新见解,这对于它们进行光合电子流的结构和功能完整性至关重要。AFM图像显示RC-LH1复合物在光合膜中密集组织,横向蛋白质扩散受到限制。4Hcyt亚基的展开代表一个多步过程,而4Hcytα螺旋的展开力约为121皮牛顿。牵拉4Hcyt也可能导致与4Hcyt N末端结合的RC L亚基的解折叠,表明RC亚基之间存在强相互作用。这项研究为光合多组分复合物的蛋白质折叠和相互作用提供了新见解,这对于它们进行光合电子流的结构和功能完整性至关重要。AFM图像显示RC-LH1复合物在光合膜中密集组织,横向蛋白质扩散受到限制。4Hcyt亚基的展开代表一个多步过程,而4Hcytα螺旋的展开力约为121皮牛顿。牵拉4Hcyt也可能导致与4Hcyt N末端结合的RC L亚基的解折叠,表明RC亚基之间存在强相互作用。这项研究为光合多组分复合物的蛋白质折叠和相互作用提供了新见解,这对于它们进行光合电子流的结构和功能完整性至关重要。4Hcyt亚基的展开代表一个多步过程,而4Hcytα螺旋的展开力约为121皮牛顿。牵拉4Hcyt也可能导致与4Hcyt N末端结合的RC L亚基的解折叠,表明RC亚基之间存在强相互作用。这项研究为光合多组分复合物的蛋白质折叠和相互作用提供了新见解,这对于它们进行光合电子流的结构和功能完整性至关重要。4Hcyt亚基的展开代表一个多步过程,并且4Hcytα螺旋的展开力约为121皮牛顿。牵拉4Hcyt也可能导致与4Hcyt N末端结合的RC L亚基的解折叠,表明RC亚基之间存在强相互作用。这项研究为光合多组分复合物的蛋白质折叠和相互作用提供了新见解,这对于它们进行光合电子流的结构和功能完整性至关重要。
更新日期:2020-04-17
down
wechat
bug