Assoc. Prof. Mueller-Cajar, Oliver

Almost all global biomass production relies on flux of carbon dioxide through the active site of the CO2-fixing enzyme rubisco. However, under current atmospheric conditions all rubiscos catalyze an energetically wasteful oxygenation reaction and function as relatively slow catalysts. We seek to identify and characterize the molecular machinery that assists rubisco performance across nature. For instance our first published story describes a detailed biochemical characterization of multiple molecular chaperones involved in remodeling substrate inhibited rubiscos found in chemoautotrophic bacteria. Related projects concerned the characterization of molecular motors of analogous function found in plants (rice), red algae and diatoms. In other work we are using both in vivo and in vitro approaches aiming to describe the protein-protein interactions involved in the architecture of the diatom pyrenoid. This compartment comprises a wide-spread strategy, where rubisco active sites are concentrated in a limited volume of the cell permitting CO2 concentration to be locally elevated by active transport. Our advances in pyrenoid biochemistry have recently allowed us to enter the rapidly developing area of compartmentation by liquid-liquid phase separation in membraneless organelles.

Research Areas