Food and Drug Administration, Frederick, Maryland 21701, United States.
C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States.
J Phys Chem B. 2024 Oct 24;128(42):10427-10433. doi: 10.1021/acs.jpcb.4c02855. Epub 2024 Oct 10.
Proteorhodopsin (PR) is a microbial proton pump that plays a significant role in phototrophy of bacteria in marine environments. Fundamental understanding of the structure-function relationship that drives proton pumping in PR has largely been elusive due to a lack of high-resolution structures of the photointermediates in the PR photocycle. Extending upon previous work, we used long-time scale molecular dynamics (MD) simulations to characterize the M state of the blue variant of PR, which represents the first proton transfer that takes place in the photocycle. Several notable structural changes occur in the M state that are hallmarks of subsequent steps in the PR photocycle, indicating that although this protein is often compared to the canonical microbial rhodopsins, such as bacteriorhodopsin, PR possesses characteristics that make it distinct among the rapidly increasing and widely variable catalog of microbial rhodopsins.
紫膜质体光驱动质子泵（PR）是一种微生物质子泵，在海洋环境中细菌的光合作用中起着重要作用。由于缺乏 PR 光循环中光中间产物的高分辨率结构，因此对驱动质子泵的结构-功能关系的基本理解在很大程度上仍难以捉摸。在以前工作的基础上，我们使用长时间尺度的分子动力学（MD）模拟来表征 PR 蓝光变体的 M 态，这代表了光循环中发生的第一次质子转移。在 M 态下发生了几个值得注意的结构变化，这些变化是 PR 光循环中后续步骤的标志，表明尽管这种蛋白质经常与经典的微生物视紫红质（如菌紫质）进行比较，但 PR 具有使其在快速增加和广泛变化的微生物视紫红质目录中与众不同的特征。
