Botanisches Institut der Universität, Universitätsstr. 1, 4 Düsseldorf 1, FRG.
EMBO J. 1983;2(6):979-86. doi: 10.1002/j.1460-2075.1983.tb01531.x.
Cytochrome b6/f complex was prepared from washed thylakoid membranes by a procedure involving detergent treatment and centrifugation in sucrose gradients. The complex is composed of at least four polypeptide species, cytochrome f which occurs in two variant forms (mol. wt. 34/33 kd), cytochrome b6 (23 kd), the high-potential Rieske iron-sulfur protein (19 kd) and a fourth subunit (17 kd) of unknown function. Transcripts for the cytochromes f, b6 and subunit 4 were found in plastid RNA, those for the Rieske iron-sulfur protein in cytosolic poly(A) RNA. Transcripts for cytochrome b6 and subunit 4 are translated in rabbit reticulocyte lysates into products of correct length. The Rieske iron-sulfur protein and the cytochrome f apoprotein appear to be made as precursors with excess sequences of 7 and 4 kd, respectively. Cytochrome f, cytochrome b6 and subunit 4 are encoded by uninterrupted plastid genes that are located in the large single-copy region of the circular DNA molecule. Each of these genes is present once per chromosome. Their location and direction of transcription have been determined by hybrid-selection mapping and by cell-free transcription/translation of various recombinant DNAs. The genes for cytochrome b6 and for subunit 4 lie near each other, but do not overlap. They are transcribed into a single message. The gene for cytochrome f maps 15 kbp away from this cluster, close to the 3' end of the gene for the large subunit of ribulosebisphosphate carboxylase/oxygenase, and is transcribed into a separate 4 kb long RNA. All these genes have the same polarities with respect to each other.
细胞色素 b6/f 复合物由经过去污剂处理和蔗糖梯度离心的洗涤类囊体膜制备而成。该复合物由至少四种多肽组成，细胞色素 f 有两种变体形式（分子质量 34/33 kd），细胞色素 b6（23 kd），高势能 Rieske 铁硫蛋白（19 kd）和第四个未知功能的亚基（17 kd）。质体 RNA 中存在细胞色素 f、b6 和亚基 4 的转录本，细胞质多聚（A）RNA 中存在 Rieske 铁硫蛋白的转录本。兔网织红细胞裂解物中细胞色素 b6 和亚基 4 的转录本可翻译为正确长度的产物。Rieske 铁硫蛋白和细胞色素 f 脱辅基蛋白似乎作为前体产生，分别带有 7 和 4 kd 的多余序列。细胞色素 f、细胞色素 b6 和亚基 4 由未中断的质体基因编码，这些基因位于圆形 DNA 分子的大单一拷贝区。每个染色体都有一个。通过杂交选择作图和各种重组 DNA 的无细胞转录/翻译，已经确定了这些基因的位置和转录方向。细胞色素 b6 和亚基 4 的基因彼此靠近，但不重叠。它们被转录成一个单一的信息。细胞色素 f 的基因位于该基因簇 15 kbp 处，靠近 RuBisCO 大亚基的 3'端，转录成一个单独的 4 kb 长的 RNA。所有这些基因彼此之间具有相同的极性。
