Research Group "Chaperonin-assisted Protein Folding" (Manajit Hayer-Hartl)
Proteins can fulfill their complex biological functions only if they have acquired their correct three-dimensional structure. The folding and assembly processes in the cell are mediated by molecular chaperones. With their help Manajit Hayer-Hartl and her Research Group “Chaperonin-assisted Protein Folding” have succeeded in reconstructing the key protein of photosynthesis “RuBisCO” in the test tube. The picture depicts the molecular structure of this important protein complex, consisting of 8 large and 8 small subunits. During photosynthesis, plants turn water and carbon dioxide into oxygen and sugar. The essential enzyme RuBisCO takes up carbon dioxide from the atmosphere to synthesize sugar molecules that then serve as building material for cells and tissues. The complex structure of RuBisCO (16 subunits) made it difficult to rebuild it in the test tube. Therefore, Manajit Hayer-Hartl used the help of two chaperone systems to fold and assemble RuBisCO. The folding chaperones, GroEL and GroES, assist the different subunits to fold properly in the test tube. Then RbcX, a special type of chaperone discovered by the researchers, staples the large subunits of RuBisCO together to form the core of the complex made of large subunits. This is followed by the docking of the small subunits to form the functional complex. Future research will be to change the RuBisCO protein so that it becomes more effective in the uptake of carbon dioxide than the natural protein, with the goal to increase crop production.