嗜热紫硫细菌RuBisCO的冷冻电镜结构研究
常圣海，张 兴，陈景华*
（1. 浙江大学冷冻电镜中心，浙江 杭州310058；2. 浙江大学医学院附属邵逸夫医院，浙江 杭州310058；3. 浙江大学生命科学学院，浙江 杭州310058）
摘 要 1,5-二磷酸羧化酶/加氧酶（Ribulose-1,5-bisphosphate carboxylase/oxygenase，RuBisCO）能够催化光合作用暗反应过程中CO2的同化过程，完成生物圈中95%的碳固定。然而RuBisCO的催化效率极低，每个RuBisCO全酶每秒钟只能催化3~10个CO2分子的转化，高温环境下，高等植物中RuBisCO的催化活性会更低。全球暖化环境下，获取高温环境下具有较高催化活性的RuBisCO突变体，既能增加作物产量，又可固定更多CO2，减缓全球暖化速度。本研究利用冷冻电镜技术获取了嗜热紫硫细菌1.9 ÅRuBisCO的精细三维结构，并分析其与其他物种RuBisCO结构上的异同，对设计高温环境下具有较高催化活性的RuBisCO突变体提供了基础。
关键词 RuBisCO；嗜热紫硫细菌；冷冻电镜
中图分类号：Q336；Q518.2；Q939.14 文献标识码：A doi:10.3969/j.issn.1000-6281.2023.01.003
Structural study of RuBisCO from Tch. Tepidum using Cryo-EM
CHANG Sheng-hai，ZHANG Xing，CHEN Jing-hua*
（1. Center of Cryo-Electron Microscopy, Zhejiang University, School of Medicine, Hangzhou Zhejiang 310058; 2. Sir Run Run Shaw Hospital, Zhejiang University, School of Medicine, Hangzhou Zhejiang 310058; 3. School of Life, Zhejiang University, Hangzhou Zhejiang 310058，China）
Abstract RuBisCO catalyzes the carbon assimilation process of photosynthesis, and fixes 95% of carbon fixation in nature. However, the catalytic efficiency of RuBisCO is low, especially in the higher plants at high temperatures. A new designed RuBisCO of higher plants with high catalytic activity under the rising global temperatures will not only increase the crop yield, but also slow down the global warming speed. In this study, the RuBisCO structure of Tch. tepidum, a kind of thermophilic sulfur bacteria was obtained by cryo-electron microscopy at the resolution of 1.9 Å, and compared its structural with other species of RuBisCOs’, which provided clues to construct a more efficient RuBisCO for higher plants against the trend of global warming.
Keywords RuBisCO；Tch. tepidum；Cryo-EM
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