Klug G, Cohen S N
Department of Genetics, Stanford University School of Medicine, California 94305.
J Bacteriol. 1988 Dec;170(12):5814-21. doi: 10.1128/jb.170.12.5814-5821.1988.
The polycistronic puf operon of Rhodobacter capsulatus encodes protein components for the photosynthetic reaction center and one of the two antenna complexes involved in the capture of light energy. We report here that deletions within specific puf genes alter the synthesis and/or assembly in the photosynthetic membranes of pigment-protein complexes not affected genetically by the deletion. The pufX gene is required for normal ratios of antenna complexes, and its deletion results in an increase of membrane-bound light-harvesting I (LHI) complex-specific proteins. Expression of pufQ in strains deleted for the genes encoding the LHI and the photosynthetic reaction center (RC) yields a novel A868 peak that has not been associated with any of the pigment-protein complexes described previously. While deletions in the RC-coding region resulted in decreased LHI absorbance, no quantitative alteration in membrane-bound LHI protein was observed, suggesting that an intact RC complex is required for correct assembly of LHI in the membrane.
荚膜红细菌的多顺反子puf操纵子编码参与光合反应中心的蛋白质组分以及参与捕获光能的两个天线复合物之一。我们在此报告，特定puf基因内的缺失会改变色素 - 蛋白质复合物在光合膜中的合成和/或组装，而这些复合物在基因上不受该缺失影响。pufX基因是天线复合物正常比例所必需的，其缺失导致膜结合的光捕获I（LHI）复合物特异性蛋白增加。在缺失编码LHI和光合反应中心（RC）的基因的菌株中表达pufQ会产生一个新的A868峰，该峰与先前描述的任何色素 - 蛋白质复合物均无关联。虽然RC编码区域的缺失导致LHI吸光度降低，但未观察到膜结合LHI蛋白的定量变化，这表明完整的RC复合物是LHI在膜中正确组装所必需的。
