Photosystem I articles from across Nature Portfolio

Photosystem I (PSI) and PSII are two large pigment–protein complexes that are responsible for converting solar energy into chemical energy. We identify the PSI assembly factor PBF8 and show that it mediates two key consecutive steps in PSI assembly, revealing major aspects of the PSI assembly pathway in land plants.

Photosystem I (PSI) is one of two large pigment–protein complexes responsible for converting solar energy into chemical energy. This study reveals the previously unknown major PSI assembly pathway in land plants.

Here the authors determine the cryoEM structure of Symbiodinium photosystem I, revealing a distinct architecture and pigment network of this light-harvesting supercomplex.

Cultivation of a new anoxygenic phototrophic bacterium from Boreal Shield lake water—representing a transition form in the evolution of photosynthesis—offers insights into how the major modes of phototrophy diversified.

NADP⁺ is the final electron acceptor for linear electron transfer in photosynthesis. Here, the authors show that the NADP pool size is modulated by its interconversion with NAD via ΔpH regulation in response to varying light conditions.

Ground truthed thermal data from a new NASA satellite combined with experimental warming data from three continents in an empirical model suggests that tropical forests are closer to a high temperature threshold than previously thought.

Robust photosynthetic light harvesting occurs in large membrane supercomplexes. Here, the authors show that supercomplexes occupy an unexpectedly large range of conformations yet maintain their efficiency due to specific, critical chlorophylls.

Dinoflagellates are ecologically important and essential to corals and other cnidarians as phytosymbionts, but their photosystems had been underexplored. Recently, photosystem I (PSI) of dinoflagellate Symbiodinium sp. was structurally characterized using cryo-Electron Microscopy (cryo-EM). These analyses revealed a distinct organization of the PSI supercomplex, including two previously unidentified subunits, PsaT and PsaU, and shed light on interactions between light harvesting antenna proteins and the PSI core. These results have implications with respect to the evolution of dinoflagellates and their association with cnidarians.

The assembly of large protein–pigment photosystem supercomplexes relies on several assembly factors. Zhang et al. describe a novel assembly factor that evolved during the terrestrialization of land plants.

Photosystem I (PSI) and PSII are two large pigment–protein complexes that are responsible for converting solar energy into chemical energy. We identify the PSI assembly factor PBF8 and show that it mediates two key consecutive steps in PSI assembly, revealing major aspects of the PSI assembly pathway in land plants.

Machine-learning algorithms for protein structure prediction can now generate models directly from sequences. However, photosynthetic assemblies represent a challenge due to additional levels of complexity arising from their multi-protein nature and presence of cofactors.

The core of the photosynthetic complex photosystem I had been assumed to require contact with its associated light-harvesting complex I to function. But a mutant Arabidopsis line lacking the components of this complex shows that a plant's photosynthetic apparatus is more adaptable to changes in its environment than previously thought.