Protein Domain : Photosystem I P840 reaction centre protein PscD IPR019608

Type	Family
Description	Oxygenic photosynthesis uses two multi-subunit photosystems (I and II) located in the cell membranes of cyanobacteria and in the thylakoid membranes of chloroplasts in plants and algae. Photosystem II (PSII) has a P680 reaction centre containing chlorophyll 'a' that uses light energy to carry out the oxidation (splitting) of water molecules, and to produce ATP via a proton pump. Photosystem I (PSI) has a P700 reaction centre containing chlorophyll that takes the electron and associated hydrogen donated from PSII to reduce NADP+ to NADPH. Both ATP and NADPH are subsequently used in the light-independent reactions to convert carbon dioxide to glucose using the hydrogen atom extracted from water by PSII, releasing oxygen as a by-product.The photosynthetic reaction centres (RCs) of aerotolerant organisms contain a heterodimeric core, built up of two strongly homologous polypeptides each of which contributes five transmembrane peptide helices to hold a pseudo-symmetric double set of redox components. Two molecules of PscD are housed within a subunit. PscD may be involved in stabilising the PscB component since it is found to co-precipitate with FMO (Fenna-Mathews-Olson BChl a-protein) and PscB. It may also be involved in the interaction with ferredoxin [ ].
Short Name	PSI_P840_PscD