小柯机器人

紫菜藻胆体能量转移的结构基础
2020-03-02 12:52

清华大学隋森芳团队揭示了紫菜藻胆体能量转移的结构基础。2020219日出版的《自然》杂志发表了这一项研究成果。

他们报道了来自红藻紫菜的14.7兆道尔顿藻胆体半电子体形状的冷冻电镜结构。在此复合物中,他们确定了706个蛋白亚基的结构,包括528个藻红蛋白、72个藻蓝蛋白、46个别藻蓝蛋白和60个接头蛋白。

此外,分离出1,598个发色团,其中包含1,430个藻红蛋白、48个藻尿素和120个藻氰素分子。与Griffithsia pacifica5的藻胆体相比,此结构分辨率得到了显著提高,这使得紫脓菌藻胆体系统的精确原子模型能够建立。

该模型揭示了接头蛋白如何影响发色团的微环境,并表明接头蛋白的芳香氨基酸与发色团的相互作用,可能是微调发色团能量状态以确保有效单向能量转移的关键因素。

据介绍,光合生物发育出各种光收集系统以适应其环境。藻胆体是在蓝藻和红藻中发现的大型光捕获蛋白复合物,尽管这些复合物中发色团的能量如何受到环境的调节尚不清楚。

附:英文原文

Title: Structural basis of energy transfer in Porphyridium purpureum phycobilisome

Author: Jianfei Ma, Xin You, Shan Sun, Xiaoxiao Wang, Song Qin, Sen-Fang Sui

Issue&Volume: 2020-02-19

Abstract: Photosynthetic organisms have developed various light-harvesting systems to adapt to their environments1. Phycobilisomes are large light-harvesting protein complexes found in cyanobacteria and red algae2,3,4, although how the energies of the chromophores within these complexes are modulated by their environment is unclear. Here we report the cryo-electron microscopy structure of a 14.7-megadalton phycobilisome with a hemiellipsoidal shape from the red alga Porphyridium purpureum. Within this complex we determine the structures of 706 protein subunits, including 528 phycoerythrin, 72 phycocyanin, 46 allophycocyanin and 60 linker proteins. In addition, 1,598 chromophores are resolved comprising 1,430 phycoerythrobilin, 48 phycourobilin and 120 phycocyanobilin molecules. The markedly improved resolution of our structure compared with that of the phycobilisome of Griffithsia pacifica5 enabled us to build an accurate atomic model of the P. purpureum phycobilisome system. The model reveals how the linker proteins affect the microenvironment of the chromophores, and suggests that interactions of the aromatic amino acids of the linker proteins with the chromophores may be a key factor in fine-tuning the energy states of the chromophores to ensure the efficient unidirectional transfer of energy.

DOI: 10.1038/s41586-020-2020-7

Source: https://www.nature.com/articles/s41586-020-2020-7

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:43.07
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

分享到:

0