Bactoriology Department, University of Wisconsin, 1550 Linden Drive, 53706, Madison, WI, USA.
Photosynth Res. 1988 Jan;19(1-2):39-61. doi: 10.1007/BF00114568.
The puf operon of the purple nonsulfur photosynthetic bacterium, Rhodobacter sphaeroides, contains structural gene information for at least two functionally distinct bacteriochlorophyll-protein complexes (light harvesting and reaction center) which are present in a fixed ratio within the photosynthetic intracytoplasmic membrane. Two proximal genes (pufBA) specify subunits of a long wavelength absorbing (i.e., 875 nm) light harvesting complex which are present in the photosynthetic membrane in ≃15 fold excess relative to the reaction center subunits which are encoded by the pufLM genes. This review summarizes recent studies aimed at determining how expression of the R. sphaeroides puf operon region relates to the ratio of individual bacteriochlorophyll-protein complexes found within the photosynthetic membrane. These experiments indicate that puf operon expression may be regulated at the transcriptional, post-transcriptional, translation and post-translational levels. In addition, this review discusses the possible role(s) of newly identified loci upstream of pufB which may be involved in regulating either synthesis or assembly of individual bacteriochrlorophyll-protein complexes as well as the pufX gene, the most distal genetic element within the puf operon whose function is still unknown.
紫细菌球形红杆菌的 puf 操纵子包含至少两种功能不同的细菌叶绿素蛋白复合物（光收集和反应中心）的结构基因信息，这些复合物在光合胞质膜内以固定比例存在。两个近端基因（pufBA）指定长波长吸收（即 875nm）光收集复合物的亚基，这些亚基在光合膜中的存在量相对于由 pufLM 基因编码的反应中心亚基过量约 15 倍。这篇综述总结了最近旨在确定球形红杆菌 puf 操纵子区域的表达如何与光合膜中发现的各个细菌叶绿素蛋白复合物的比例相关的研究。这些实验表明，puf 操纵子的表达可能在转录、转录后、翻译和翻译后水平受到调节。此外，本文还讨论了 pufB 上游新鉴定的基因座可能在调节单个细菌叶绿素蛋白复合物的合成或组装中的可能作用，以及 puf 操纵子中最远的遗传元件 pufX 基因，其功能仍不清楚。
