Structures and mechanisms of enzymes involved in bacterial chlorophyll biosynthesis

• Applicants: Professor Dr. Dieter Jahn; Dr. Jürgen Moser
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2006 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 27234646

Chlorophylls and bacteriochlorophylls are essential for the capturing of the global energy demand. In bacteria and plants, these pigment molecules are essential parts of the photosynthetic apparatus which is responsible for the conversion of light into chemical energy. Our work is focused on the molecular understanding of the following (bacterio)chlorophyll biosynthetic enzymes: 3-vinyl bacteriochlorophyllide a hydratase (BchF) and 3-hydroxyethyl bacteriochlorophyllide a dehydrogenase (BchC) catalyze the penultimate steps of bacteriochlorophyll a synthesis. O2-dependent or O2-independent Mg protoporphyrin IX monomethylester cyclase is essential for the synthesis of the fifth ring system found in all chlorophylls. The identification and characterization of all essential cyclase protein subunits is a central goal of this project. Light-dependent protochlorophyllide oxidoreductase (LPOR) performs a strictly light-dependent catalysis. Novel catalytic principles employed by enzymes carrying multiple cofactors (e.g. coenzyme B12, S-adenosyl methionine or diiron centers) are expected. Crystal structure determination in combination with biochemical and biophysical analyses will reveal the atomistic understanding of the late steps of (bacterio)chlorophyll biosynthesis.

• DFG Programme: Research Grants