CO2 concentrating mechanisms in cyanobacteria: molecular components, their diversity and evolution

Cyanobacteria have evolved an extremely effective single-cell CO(2) concentrating mechanism (CCM). Recent molecular, biochemical and physiological studies have significantly extended current knowledge about the genes and protein components of this system and how they operate to elevate CO(2) around Rubisco during photosynthesis. The CCM components include at least four modes of active inorganic carbon uptake, including two bicarbonate transporters and two CO(2) uptake systems associated with the operation of specialized NDH-1 complexes. All these uptake systems serve to accumulate HCO(3)(-) in the cytosol of the cell, which is subsequently used by the Rubisco-containing carboxysome protein micro-compartment…