MECHANISM OF THE ENERGY-STORING REACTIONS IN PHOTOSYNTHETIC ORGANISMS

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 在光合作用系统中导致长期能量储存的化学反应发生在膜结合的反应中心复合体和组成电子传输链的一组相关蛋白质中。我们研究的中心目标之一是确定导致该系统吸收的几乎每个光子都会产生稳定产品这一事实的分子参数。为此，我们使用了许多技术，包括超快激光闪光光解和UV-Vis，荧光和电子自旋共振光谱，以及生化和分子生物学分析，对天线复合体、反应中心、电子传递蛋白和分离的色素进行了各种动力学、热力学和结构测量。 光合作用和其他代谢过程的出现，如固氮，对地球上高级生命的进化产生了深远的影响。我们对整个细菌基因组的分析表明，这些代谢过程有复杂的进化历史，包括大量的水平基因转移。我们还使用了基因组、分子进化技术和生化分析相结合的方法来鉴定和表征具有新活性的未知酶复合体。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The chemical reactions leading to long-term energy storage in photosynthetic systems take place within the membrane-bound reaction center complex and an associated group of proteins that make up an electron transport chain. One of the central goals of our research is to identify the molecular parameters responsible for the fact that essentially every photon absorbed by the system leads to stable products. To this end, we do a variety of kinetic, thermodynamic and structural measurements on antenna complexes, reaction centers, electron transport proteins and isolated pigments, using a number of techniques, including ultrafast laser flash photolysis and UV-VIS, fluorescence and electron spin resonance spectroscopies, as well as biochemical and molecular biological analysis. The appearance of photosynthesis and other metabolic processes such as nitrogen fixation had profound effects on the evolution of advanced life on Earth. Our analysis of whole bacterial genomes has revealed that these metabolic processes have complex evolutionary histories, including substantial horizontal gene transfer. We have also used a combination of genomic, molecular evolution techniques and biochemical analysis to identify and characterize previously unknown enzyme complexes with novel activities.