|Photosynthetic organisms provide us with food and other materials by using light energy from the sun to capture carbon dioxide from the atmosphere to make usable sugars. Almost all CO2 enters the biosphere via the enzyme ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco). In spite of the crucial importance of this process Rubisco is non-specific and slow, which has forced nature to hugely overexpress the protein, or to use tricks such as biochemical or biophysical carbon concentrating mechanisms to saturate the enzyme with substrate. |
Genomic studies have uncovered that Nature possesses a great diversity of Rubiscos and associated protein machinery to perform the task of CO2 capture, much of it poorly characterized. Research in my laboratory aims to mechanistically describe the biochemistry of CO2-fixation related machinery. By increasing our understanding of the sophisticated mechanisms that have evolved in remote branches of the tree of life, we hope to provide knowledge that can later be applied to improving the photosynthetic efficiency of crop species.
The journey has led from experiments exploring the artificial or directed evolution of Rubisco in E. coli to detailed structural and mechanistic investigations into molecular chaperones, so called Rubisco activases, that repair inactivated Rubiscos. Recently we have entered the realm of soft matter physics (liquid liquid phase separation) by exploring the manner by which microalgae compartmentalize the enzyme in a small volume to enable an increase of local carbon dioxide concentrations to be achieved.
Towards translating our interests we have also turned our attention towards the potential use of eukaryotic microalgae as a synthetic biology platform. This involves both the utilization and implementation of heterologous CO2 fixation machinery, as well as the potential to channel the photosynthate towards compounds of scientific and commercial interest.
We are always interested in hosting promising young scientists that have a clear idea in how their future plans intersect with the group's interests.
- Tsai YC, Ye F, Liew L, Liu D, Bhushan S, Gao YG, Mueller-Cajar O. (2020). Insights into the mechanism and regulation of the CbbQO-type Rubisco activase, a MoxR AAA+ ATPase. Proceedings of the National Academy of Sciences of the United States of America (PNAS), 117(1), 381-387.
- Shivhare D, Ng J, Tsai YC, Mueller-Cajar O. (2019). Probing the rice Rubisco-Rubisco activase interaction via subunit heterooligomerization. Proceedings of the National Academy of Sciences of the United States of America (PNAS), 116(48), 24041-24048.
- Wunder T, Cheng SLH, Lai SK, Li HY, Mueller-Cajar O. (2018). The phase separation underlying the pyrenoid-based microalgal Rubisco supercharger. Nature Communications, 9, 5076.
- Shivhare D, Mueller-Cajar O. (2017). In Vitro Characterization of Thermostable CAM Rubisco Activase Reveals a Rubisco Interacting Surface Loop. Plant Physiology, 174(3), 1505-1516.
- Jin S, Sun J, Wunder T, Tang D, Cousins AB, Sze SK, Mueller-Cajar O, Gao YG. (2016). Structural insights into the LCIB protein family reveals a new group of β-carbonic anhydrases.. Proceedings of the National Academy of Sciences of the United States of America (PNAS), 113(51), 14716-14721.