Chaperones fold Rubisco
More energy with less water
Despite all the difficulties it presents, the objective behind this research is worthwhile: on the one hand, algae or plants with an optimized Rubisco variant could be used as a weapon in the fight against the rising carbon dioxide concentration in the atmosphere; on the other hand, the availability of such turbo plants with a significantly higher growth rate would also be a huge advantage for agriculture. “We could benefit from a form of Rubisco that is 10 or 15 percent more efficient,” says Manajit Hayer-Hartl.
It is not just a question of accelerating growth, but of even making it possible in the first place in some locations, as more efficient conversion of carbon dioxide into sugar reduces the plant’s water consumption. As a result, in the future, agricultural activity would be possible in areas that are currently too arid for today’s crop plants – and such areas are set to expand further due to the increasing scarcity of water on Earth.
Proteins can function only if their amino acid chains are correctly folded. Like the chaperones of the 19th century whose job it was to shield young ladies from improper influences, special enzymes in cells ensure that proteins do not end up on the wrong path and assume the wrong form. Some chaperones take the form of a cylinder in which only a single molecule can fold. Such chaperones found in bacteria, chloroplasts and mitochondria are known as chaperonins. A lack of functional chaperones can result in the clumping of proteins and cause various diseases, such as Alzheimer’s and Huntington’s chorea.
Photosynthesis involves the production of carbohydrates from carbon dioxide and water with the help of solar energy. The process can be subdivided into two connected stages: The light reactions (photo part) make energy available for the water to be split into electrons, protons and oxygen. The energy-rich electrons and protons are used in the Calvin cycle (synthesis part) to convert carbon dioxide into sugar.
Photosynthesis, a veritable stroke of genius on the part of nature, makes the existence of higher life forms possible. If it can be optimized, it may be able to make an even greater contribution to the resolution of future energy problems. Manajit Hayer-Hartl and Ulrich Hartl are currently working on this possibility at the Max Planck Institute of Biochemistry in Martinsried.
Text: Harald Rösch