Characterization of a spinach psbS cDNA encoding the 22 kDa protein of photosystem II

Abstract

An intrinsic 22 kDa polypeptide is found associated with the oxygen-evolvin~ photosystem 11 (PSII) core complex in all green plants and cyanobaeteria so far examined, although it does not appear to be required l'or oxygen evolution. Amino acid ~equenee itfforrnation obtained from the purified 22 kDa protein was used to construct a probe that was employed to isolate a full-length eDNA clone encoding the 274-residue precursor of the 22 kDa protein. Hydropathy plot analysis predicts the existence of four membrane-spanning helices in the mature protein, The two halves of the approxlmntely 200-resld uc mature protein show high sequence similarity to each other, suggesting that the psbS gene arose from an internal gene duplication. The 22 kDa protein has some sequence similarity to chlorophyll a/b.binding proteins.

Molecular and Global Time-resolved Analysis of a psbSGene Dosage Effect on pH- and Xanthophyll Cycle-dependent Nonphotochemical Quenching in Photosystem II

“…PsbS was originally identified as a 22-kDa intrinsic subunit of the PSII oxygen-evolving complex in spinach (28,29,48), where it was suggested to be situated between the reaction center core and the peripheral light-harvesting antenna (49). However, the exact functional location of PsbS in PSII has been disputed, because it did not appear to be present in dimeric PSII supercomplexes studied by electron microscopy (50,51).…”

“…PsbS is a member of the light-harvesting complex (LHC) protein superfamily (28,29). PsbS has been reported to bind substoichiometric levels of V (30), although recent attempts to purify or reconstitute the protein with bound pigments were unsuccessful (31).…”

Chlamydomonas reinhardtii PsbS Protein Is Functional and Accumulates Rapidly and Transiently under High Light

“…PsbS belongs to the Lhc supergene family, but it has the unique property of being the only member with four transmembrane helices instead of the more common three-helix organization (Kim et al, 1992). Because no pigment binding has been detected either by biochemical analysis (Bonente et al, 2008a) or in in the recent crystal structure (Fan et al, 2015), it is very likely that PsbS is not the quenching site during NPQ.…”

Genetic mapping of genes for twelve nuclear‐encoded polypeptides associated with the thylakoid membranes in Beta vulgaris L

“…They dinated per se, and also with those originating in the organrepresent at least five subfamilies, encoding the LHCI and II elle, to ensure the correct biogenesis of the thylakoid memapoproteins, ELIPs, the apoproteins of the minor antenna brahe complexes in time, space, quantity and induceability, CP24/CP26/CP29, and the recently described PsbS product, and how during evolution these different promoters have respectively. The tbrmer three originate in gene clusters, the been integrated into the network of signal pathways that conlatter in single-copy genes in spinach and tomato [18,25]. Only trol their (often concerted) expression.…”

“…[16]). Thus, gedisplay a remarkable degree of general homology and prenetic mapping of loci for proteins involved in photosynthesis dieted secondary structure [25] but that the transit peptides can substantially extend our knowledge on nuclear genes in (and flanking sequences, where known) between (not within) general. Combined with novel approaches, it can provide acsubfamilies are entirely different [18,26] have suggested that cess to crucial questions that were not accessible before, and the Lhc family, unlike the RbcS family, must represent a thus open a wide field of experimentation.…”