[Hsiu-An Chu] New structural and mechanistic insights into functional roles of cytochrome b₅₅₉ in photosystem II

Cytochrome (Cyt) b₅₅₉ is a key component of the photosystem II complex (PSII) for its assembly and proper function. Previous studies have suggested that Cyt _b559 has functional roles in the early assembly of PSII and in secondary electron transfer pathways that protect the PSII against photoinhibition. In addition, Cyt b₅₅₉ in various PSII preparations exhibited multiple different redox potential forms. However, the precise functional roles of Cyt b₅₅₉ in PSII remain unclear. Recent site-directed mutagenesis studies combined with functional genomics and biochemical analysis as well as high-resolution x-ray crystallography and cryo-electron microscopy studies of native, inactive and assembly intermediates of PSIIs have provided important new structural and mechanistic insights into the functional roles of Cyt b₅₅₉. This mini-review gives an overview of these new exciting results and their significance for understanding the structural and functional roles of Cyt b₅₅₉ in PSII.

Yi-Fang Chiu and Hsiu-An Chu, Front. Plant Sci., 08 June 2022 | https://doi.org/10.3389/fpls.2022.914922