美国西北大学Amy C. Rosenzweig课题组揭示脂质双层中酶颗粒甲烷单加氧酶 (pMMO)结构和活性的恢复。2022年3月18日出版的《科学》杂志发表了这项成果。

他们表明，用从天然生物体中提取的脂质在纳米圆盘中重构 pMMO 可以恢复甲烷氧化活性。通过冷冻电镜以 2.14 至 2.46 埃的分辨率确定的多个纳米圆盘嵌入 pMMO 结构揭示了脂质环境中 pMMO 的结构。所得模型包括稳定脂质、在先前结构中未观察到的 PmoA 和 PmoC 亚基区域，以及 PmoC 亚基中先前未检测到的具有相邻疏水腔的铜结合位点。 这些结构为理解和设计 pMMO 功能提供了一个修订的框架。

研究人员表示，使用 pMMO 进行的细菌甲烷氧化有助于去除环境中的甲烷，这是一种强效温室气体。使用非活性、去污剂溶解的 pMMO 确定的晶体结构缺少与拟议的活性位点相邻的几个保守区域。

附：英文原文

Title: Recovery of particulate methane monooxygenase structure and activity in a lipid bilayer

Author: Christopher W. Koo, Frank J. Tucci, Yuan He, Amy C. Rosenzweig

Issue&Volume: 2022-03-18

Abstract: Bacterial methane oxidation using the enzyme particulate methane monooxygenase (pMMO) contributes to the removal of environmental methane, a potent greenhouse gas. Crystal structures determined using inactive, detergent-solubilized pMMO lack several conserved regions neighboring the proposed active site. We show that reconstituting pMMO in nanodiscs with lipids extracted from the native organism restores methane oxidation activity. Multiple nanodisc-embedded pMMO structures determined by cryo–electron microscopy to 2.14- to 2.46-angstrom resolution reveal the structure of pMMO in a lipid environment. The resulting model includes stabilizing lipids, regions of the PmoA and PmoC subunits not observed in prior structures, and a previously undetected copper-binding site in the PmoC subunit with an adjacent hydrophobic cavity. These structures provide a revised framework for understanding and engineering pMMO function.

DOI: abm3282

Source: https://www.science.org/doi/10.1126/science.abm3282