Researchers at the Max Planck Institute of Biochemistry have succeeded in
producing functional plant Rubisco in a bacterium, allowing genetic
engineering of the enzyme. Rubisco, a critical enzyme in photosynthesis,
catalyzes the first step in carbohydrate production in plants, the fixation
of CO2 from the atmosphere.
The researchers, led by Dr. Manajit Hayer-Hartl, generated functional plant
Rubisco in a bacterial host by simultaneously expressing plant chaperones
and Rubisco in the same cells. This enabled the scientists to understand the
complex assembly pathway of Rubisco, and also modify the Rubisco gene to
improve its properties. Once they have obtained a Rubisco variant with a
desired trait, they can insert the modified gene back into the plant cells,
a key-step towards improving photosynthesis through Rubisco engineering.
"The bacterial expression system resembles an assembly line for cars.
Whereas previously, every optimized variant of Rubisco had to be
painstakingly expressed in a transgenic plant, which takes a year or more to
generate - like building a car by hand - we can now make hundreds or
thousands of Rubisco variants in days or weeks. It is like building cars in
an automated assembly line," explains Dr. Hayer-Hartl.