Graduate Students Mini-Symposium IV 2022

Program

16:00h Daniel Marchal, AG Erb
"Realizing synthetic carboxylation modules to improve photosynthesis”

Photosynthesis plays a crucial role in the global carbon cycle it converts CO₂ into organic compounds that are used as feedstock by heterotrophic organisms. However, the efficiency of photosynthesis via the Calvin-Benson cycle is diminished by Rubisco’s inability to reliably distinguish between O₂ and CO₂. Photorespiration that is required to recycle 2-phosphoglycolate, the product of Rubico’s oxygenation side reaction, involves the undesired loss of carbon. We developed two synthetic carboxylation modules circumventing this loss of carbon and instead fixing additional CO₂. Structure-guided enzyme engineering coupled with large-scale screening of mutagenesis libraries evolved new-to-nature activities providing novel possibilities to improve CO₂ fixation.

16:30 h Maria Isabel Pérez López, AG Sourjik
"Lack of HflK-HflC affects the respiratory activity of E. coli"

HflK-HflC is a highly conserved membrane complex that belongs to a family of proteins conserved in all domains of life. It’s only established function in E. coli is the regulation of the FtsH metalloprotease. We observed that lack of HflK-HflC affects the respiration-dependent growth and perturbs the abundance of cytochrome ubiquinol oxidases. We hypothesize that these effects might be due to reduced levels of ubiquinol that is essential for aerobic respiration. Consistently, loss of the HflK-HflC complex also decreases membrane potential and the respiratory activity.