This minireview covers the research carried out in recent years into differ-ent aspects of the function of the flavoproteins involved in cyanobacterial photosynthetic electron transfer from photosystem I to NADP + , flavodox-in and ferredoxin–NADP + reductase. Interactions that stabilize protein– flavin complexes and tailor the midpoint potentials in these proteins, as well as many details of the binding and electron transfer to protein and ligand partners, have been revealed.
