Emergence of new regulatory mechanisms in the Benson-Calvin pathway via protein-protein interactions: a glyceraldehyde-3-phosphate dehydrogenase/CP12/phosphoribulokinase complex.

Protein-protein interactions are involved in many metabolic pathways. This review will focus on the role of such associations in CO2 assimilation (Benson-Calvin cycle) and especially on the involvement of a GAPDH/CP12/PRK complex which has been identified in many photosynthetic organisms and may have an important role in the regulation of CO2 assimilation. The emergence of new kinetic and regulatory properties as a consequence of protein-protein interactions will be addressed as well as some of the questions raised by the existence of these supramolecular complexes such as composition, function, and assembly pathways. The presence and role of small intrinsically unstructured proteins like the 8.5 kDa protein CP12, involved in the regulation and/or assembly of these complexes will be discussed.