Iron deficiency impairs energy capture and photosynthetic electron transport, leading to remodeling of photosynthetic complexes, mainly impacting photosystem I. In Anabaena sp. PCC 7120, this remodeling includes a change in the oligomeric state of PSI and the formation of a unique antenna system with covalently attached IsiA2-PSI complex, along with other IsiA homologs. This study describes the spectroscopic properties of three types of IsiA2-containing complexes and details their energy-transfer efficiency. Based on spectral data and Mass-Spec analysis of these complexes, a proposed model suggests that antenna modulation, influenced by the intracellular redox state, could regulate PSI activity during iron stress.