Origin, phylogeny, evolution and structural basis of light-driven protochlorophyllide reduction

• Applicants: Dr. Thomas Drepper; Dr. Ulrich Krauss
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 258093065

The reduction of protochlorophyllide represents one key steps in the complex biosynthesis pathway yielding (bacterio)chlorophyll. In oxygenic phototrophs such as plants, algae and cyanobacteria this step is catalyzed by light-driven protochlorophyllide (Pchlide) oxidoreductases (LPORs). In an evolutionary context, it is currently widely accepted that LPORs were first -invented- in cyanobacteria and were then transferred via endosymbiosis to plants and algae. In contrast to this long held paragdigm, we have recently identified a functional light-driven LPOR in the anoxygenic alpha-proteobacterium Dinoroseobacter shibae DFL12T (unpublished data, see preliminary work). This raises far reaching questions regarding the evolution of chlorophyll biosynthesis and photosynthesis and suggests that additional functionally diverse LPORs might be found in e.g. unculturable strains and/or specialized microbes. The proposal aims to exploit the yet unexplored sequence diversity of metagenomic/environmental sources to elucidate the evolutionary origin, phylogeny, as well as the structural and functional basis of light-driven protochlorophyllide reduction. To achieve these goals, it is necessary to combine the interdisciplinary expertise of microbiologists, molecular biologists, biochemists, bioinformaticians and structural biologists. While in vivo and in vitro functional and structural data (working groups Krauss and Drepper) will provide broad insight into functional adaptation and mechanistic aspects of light-driven Pchlide reduction by the LPOR family of enzymes, the evolutionary perspective which will be established by the working group of Arndt von Haeseler is expected to provide a new dimension and enriched scope.

• DFG Programme: Research Grants
• International Connection: Austria
• Participating Institution: Universität Wien ; Center for Integrative Bioinformatics Vienna (CIBIV)
• Partner Organisation: Fonds zur Förderung der wissenschaftlichen Forschung (FWF)
• Participating Persons: Professorin Dr. Renu Batra-Safferling, Ph.D.; Privatdozent Dr. Joachim Granzin; Professor Dr. Arndt von Haeseler