The low molecular mass subunits of the photosynthetic supracomplex, photosystem II
2004 (English)In: Biochimica et Biophysica Acta - Bioenergetics, ISSN 0005-2728, E-ISSN 1879-2650, Vol. 1608, no 2-3, 75-96 p.Article in journal (Refereed) Published
The photosystem II (PSII) complex is located in the thylakoid membrane of higher plants, algae and cyanobacteria and drives the water oxidation process of photosynthesis, which splits water into reducing equivalents and molecular oxygen by solar energy. Electron and X-ray crystallography analyses have revealed that the PSII core complex contains between 34 and 36 transmembrane α-helices, depending on the organism. Of these helices at least 12-14 are attributed to low molecular mass proteins. However, to date, at least 18 low molecular mass (<10 kDa) subunits are putatively associated with the PSII complex. Most of them contain a single transmembrane span and their protein sequences are conserved among photosynthetic organisms. In addition, these proteins do not have any similarity to any known functional proteins in any type of organism, and only two of them bind a cofactor. These findings raise intriguing questions about why there are so many small protein subunits with single-transmembrane spans in the PSII complex, and their possible functions. This article reviews our current knowledge of this group of proteins. Deletion mutations of the low molecular mass subunits from both prokaryotic and eukaryotic model systems are compared in an attempt to understand the function of these proteins. From these comparisons it seems that the majority of them are involved in stabilization, assembly or dimerization of the PSII complex. The small proteins may facilitate fast dynamic conformational changes that the PSII complex needs to perform an optimal photosynthetic activity.
Place, publisher, year, edition, pages
2004. Vol. 1608, no 2-3, 75-96 p.
Arabidopsis, Function, PS2, Small protein, Synechocystis, cytochrome b559, membrane protein, protein, protein psbe, protein psbh, protein psbi, protein PsbJ, protein psbk, protein PsbL, protein psbm, protein psbn, protein psbr, protein psbtc, protein psbtn, protein psbw, protein psbx, protein psby, protein psbz, protein subunit, unclassified drug, binding affinity, chloroplast, comparative study, deletion mutant, dimerization, eukaryote, genetic analysis, genetic code, molecular weight, mutation, nonhuman, photosynthesis, priority journal, prokaryote, protein analysis, protein assembly, protein binding, protein function, protein localization, protein stability, protein structure, review, sequence analysis, sequence homology, structure analysis, Amino Acid Sequence, Chloroplasts, Crystallography, Cyanobacteria, Molecular Sequence Data, Peptides, Phosphoproteins, Photosystem II Protein Complex, Plant Proteins, algae, Embryophyta, Eukaryota, Prokaryota
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:sh:diva-23202DOI: 10.1016/j.bbabio.2003.12.004PubMedID: 14871485ScopusID: 2-s2.0-1042290470OAI: oai:DiVA.org:sh-23202DiVA: diva2:716794