Apoprotein structure in the LH2 complex from Rhodopseudomonas acidophila strain 10050: Modular assembly and protein pigment interactions
Apoprotein structure in the LH2 complex from Rhodopseudomonas acidophila strain 10050: Modular assembly and protein pigment interactions
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DOI：
10.1006/jmbi.1997.0966
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发表时间：
1997-05-02
影响因子：
5.6
通讯作者：
Isaacs, NW
中科院分区：
文献类型：
--
作者：
Prince, SM;Papiz, MZ;Isaacs, NW
嗜酸红假单胞菌菌株 10050 的外周光捕获复合物的精细结构揭示了一种膜蛋白，该膜蛋白在跨膜区域中具有完全范德华性质的蛋白质-蛋白质相互作用。复合物形成的主要因素似乎是膜外氢键（表明每个脱辅基蛋白必须实现接近其最终结构的折叠才能寡聚）、跨膜区域内的蛋白质-色素和色素-色素相互作用。已知色素分子在细菌光收集器的形成以及它们在膜内结构接触的广泛介导中发挥重要作用。 膜证实了这一点。决定脱辅基蛋白二级结构的氨基酸残基影响复合物的寡聚状态。色素阵列的组装由 LH2 的脱辅基蛋白控制。然而，每个色素分子的特定环境直接受到少数蛋白质接触的影响。这些接触产生的功能效应不能归因于单一原因，例如发色团重叠循环的排列不仅提供了能量离域和存储特性，而且还对低聚物尺寸、颜料变形模式和颜料化学环境产生影响，所有这些都会改变复合物的精确功能。评估颜料阵列的位点能量需要考虑多种效应，包括异质颜料变形、局部环境中的电荷分布和机械相互作用。 (C) 1997 学术出版社有限公司。
The refined structure of the peripheral light-harvesting complex from Rhodopseudomonas acidophila strain 10050 reveals a membrane protein with protein-protein interactions in the trans-membrane region exclusively of a van der Waals nature. The dominant factors in the formation of the complex appear to be extramembranous hydrogen bonds (suggesting that each apoprotein must achieve a fold close to its final structure in order to oligomerize), protein-pigment and pigment-pigment interactions within the membrane-spanning region, The pigment molecules are known to play an important role in the formation of bacterial light-harvesters, and their extensive mediation of structural contacts within the membrane bears this out. Amino acid residues determining the secondary structure of the apoproteins influence the oligomeric state of the complex.The assembly of the pigment array is governed by the apoproteins of LH2. The particular environment of each of the pigment molecules is, however, influenced directly by few protein contacts. These contacts produce functional effects that are not attributable to a single cause, e.g. the arrangement of an overlapping cycle of chromophores not only provides energy delocalisation and storage properties, but also has consequences for oligomer size, pigment distortion modes and pigment chemical environment, all of which modify the precise function of the complex. The evaluation of site energies for the pigment array requires the consideration of a number of effects, including heterogeneous pigment distortions, charge distributions in the local environment and mechanical interactions. (C) 1997 Academic Press Limited.