科學家報導綠硫細菌光合作用反應中心複合物冷凍電鏡結構
作者:
小柯機器人發布時間:2020/11/22 23:53:03
浙江大學基礎醫學院張興課題組與中國科學院植物研究所匡廷雲/沈建仁課題組合作報導了綠硫細菌Chlorobaculum tepidum內周捕光天線FMO-反應中心複合體 (FMO-GsbRC) 的2.7埃冷凍電鏡結構。該研究於2020年11月20日發表於國際一流學術期刊《科學》。
研究人員表示,綠硫細菌(GSB)的光合作用系統包含外周捕光天線綠小體(chlorosome)、集光Fenna-Matthews-Olson蛋白(FMO)和反應中心(GsbRC)。
研究人員使用冷凍電鏡來確定了來自綠硫細菌的FMO-GsbRC超複合物的2.7埃結構。與其他已知的I型RC相比,GsbRC結合的 (bacterio)chlorophylls [(B)Chls]少得多,並且(B)Chls的組織與光系統II中的相似。如同在其他RC中所見,GsbRC中的兩個BChl層不是通過Chls連接的,而是與兩個類胡蘿蔔素衍生物相關聯。在FMO的BChl與GsbRC之間觀察到相對較長的22至33埃的距離,這與這些實體之間的低效率能量傳遞相一致。該結構包含I型和II型RC的共同特徵,並提供了對光合作用RC進化的了解。
附:英文原文
Title: Architecture of the photosynthetic complex from a green sulfur bacterium
Author: Jing-Hua Chen, Hangjun Wu, Caihuang Xu, Xiao-Chi Liu, Zihui Huang, Shenghai Chang, Wenda Wang, Guangye Han, Tingyun Kuang, Jian-Ren Shen, Xing Zhang
Issue&Volume: 2020/11/20
Abstract: The photosynthetic apparatus of green sulfur bacteria (GSB) contains a peripheral antenna chlorosome, light-harvesting Fenna-Matthews-Olson proteins (FMO), and a reaction center (GsbRC). We used cryo–electron microscopy to determine a 2.7-angstrom structure of the FMO-GsbRC supercomplex from Chlorobaculum tepidum. The GsbRC binds considerably fewer (bacterio)chlorophylls [(B)Chls] than other known type I RCs do, and the organization of (B)Chls is similar to that in photosystem II. Two BChl layers in GsbRC are not connected by Chls, as seen in other RCs, but associate with two carotenoid derivatives. Relatively long distances of 22 to 33 angstroms were observed between BChls of FMO and GsbRC, consistent with the inefficient energy transfer between these entities. The structure contains common features of both type I and type II RCs and provides insight into the evolution of photosynthetic RCs.
DOI: 10.1126/science.abb6350
Source: https://science.sciencemag.org/content/370/6519/eabb6350
Science:《科學》,創刊於1880年。隸屬於美國科學促進會,最新IF:41.037