The Reaction Center from Green Sulfur Bacteria
The Reaction Center from Green Sulfur Bacteria
复制标题
绿硫细菌的反应中心
DOI：
10.1007/0-306-47954-0_30
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
G. Hauska
中科院分区：
文献类型：
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作者：
U. Feiler;G. Hauska
绿色硫细菌反应中心通常被认为是光系统I的对应物。然而，他们仍然很差的特点很长一段时间，因为主要的兴趣是针对了解独特的天线系统的绿色细菌，所谓的绿色体。在1990年至1995年期间，绿色硫细菌反应中心的研究取得了许多令人兴奋的进展。绿色硫细菌、日光细菌和光系统I的反应中心之间的重要相似性已经被发现，例如存在相同的电子受体组和相似的多肽组成。此外，与紫色细菌型反应中心的相似之处已经被描述。这些包括作为主要供体的细菌叶绿素二聚体和作为电子供体的P840的反应中心相关的细胞色素亚基的存在。然而，最令人惊讶的是，只有一个基因编码的二聚体，大反应中心亚基的发现。这一特征不仅与光系统I相反，而且与紫色细菌型反应中心相反，它提出了本章讨论的有趣的进化问题。已经表明，这两种类型的反应中心，即紫色细菌型和光系统I型反应中心，具有共同的特征，例如电荷分离过程、所涉及的那些色素和主要多肽的类似组织。所有这一切都导致了这样的猜测，即不同类型的光合反应中心有一个共同的进化起源。本文综述了绿色硫细菌反应中心的结构和功能，并与其他光系统I型和紫色细菌反应中心进行了比较。
Green sulfur bacterial reaction centers have been usually cited as counterparts of Photosystem I. However, they have remained poorly characterized for a long time, since the main interest was directed towards understanding the unique antenna system of green bacteria, the so-called chlorosomes. Many exciting developments in green sulfur bacterial reaction center research have occurred during the years 1990 to 1995. Important similarities between the reaction centers of green sulfur bacteria, heliobacteria, and Photosystem I have been discovered, such as the presence of the same set of electron acceptors and a similar polypeptide composition. Furthermore, similarities to the purple bacterial-type reaction centers have been described. These include the presence of a bacteriochlorophyll dimer as the primary donor and a reaction-center-associated cytochrome subunit as electron donor to P840. Most surprising, however, has been the discovery of only one gene coding for the dimeric, large reaction center subunits. This feature is in contrast, not only to Photosystem I, but also, to purple bacterial-type reaction centers, and it has raised interesting evolutionary questions which are discussed in this chapter. It has been shown that both types of reaction centers, i.e. purple bacterial- and Photosystem I -type reaction centers share common features, such as the charge separation processes, those pigments involved and a similar organization of the main polypeptides. All this led to the speculation that the different kinds of photosynthetic reaction centers have a common evolutionary origin. In this review we summarize the current state of knowledge about the green sulfur bacterial reaction center structure and function and compare these with those of other Photosystem I-type and purple bacterial reaction centers.