H
IPR036512

Photosystem II PsbZ superfamily

InterPro entry
Short namePSII_PsbZ_sf
Overlapping entries
 

Description

PSII is a multisubunit protein-pigment complex containing polypeptides both intrinsic and extrinsic to the photosynthetic membrane
[1, 2, 3, 6]
. Within the core of the complex, the chlorophyll and β-carotene pigments are mainly bound to the antenna proteins CP43 (PsbC) and CP47 (PsbB), which pass the excitation energy on to the reaction centre proteins D1 (Qb, PsbA) and D2 (Qa, PsbD) that bind all the redox-active cofactors involved in the energy conversion process. The PSII oxygen-evolving complex (OEC) oxidises water to provide protons for use by PSI, and consists of OEE1 (PsbO), OEE2 (PsbP) and OEE3 (PsbQ). The remaining subunits in PSII are of low molecular weight (less than 10kDa), and are involved in PSII assembly, stabilisation, dimerisation, and photo-protection
[5]
.

This superfamily represents PsbZ (Ycf9), which is a core low molecular weight transmembrane protein of photosystem II in thylakoid-containing chloroplasts of cyanobacteria and plants. It is thought to be located at the interface of PSII and LHCII (light-harvesting complex II) complexes, the latter containing the light-harvesting antenna. PsbZ appears to act as a structural factor, or linker, that stabilises the PSII-LHCII supercomplexes, which fail to form in PsbZ-deficient mutants. This may in part be due to the marked decrease in two LHCII antenna proteins, CP26 and CP29, found in PsbZ-deficient mutants, which result in structural changes, as well as functional modifications in PSII
[4]
. PsbZ may also be involved in photo-protective processes under sub-optimal growth conditions. Structurally, PsbZ has two antiparallel transmembrane helices.

References

1.Structural insights into photosystem II assembly. Zabret J, Bohn S, Schuller SK, Arnolds O, Moller M, Meier-Credo J, Liauw P, Chan A, Tajkhorshid E, Langer JD, Stoll R, Krieger-Liszkay A, Engel BD, Rudack T, Schuller JM, Nowaczyk MM. Nat Plants 7, 524-538, (2021). View articlePMID: 33846594

2.Crystal structure of oxygen-evolving photosystem II from Thermosynechococcus vulcanus at 3.7-A resolution. Kamiya N, Shen JR. Proc. Natl. Acad. Sci. U.S.A. 100, 98-103, (2003). View articlePMID: 12518057

3.The evolutionary development of the protein complement of photosystem 2. Raymond J, Blankenship RE. Biochim. Biophys. Acta 1655, 133-9, (2004). PMID: 15100025

4.The chloroplast gene ycf9 encodes a photosystem II (PSII) core subunit, PsbZ, that participates in PSII supramolecular architecture. Swiatek M, Kuras R, Sokolenko A, Higgs D, Olive J, Cinque G, Muller B, Eichacker LA, Stern DB, Bassi R, Herrmann RG, Wollman FA. Plant Cell 13, 1347-67, (2001). View articlePMID: 11402165

5.The low molecular mass subunits of the photosynthetic supracomplex, photosystem II. Shi LX, Schroder WP. Biochim. Biophys. Acta 1608, 75-96, (2004). PMID: 14871485

6.Thylakoid membrane lipid sulfoquinovosyl-diacylglycerol (SQDG) is required for full functioning of photosystem II in <i>Thermosynechococcus elongatus</i>. Nakajima Y, Umena Y, Nagao R, Endo K, Kobayashi K, Akita F, Suga M, Wada H, Noguchi T, Shen JR. J Biol Chem 293, 14786-14797, (2018). PMID: 30076221

GO terms

This website requires cookies, and the limited processing of your personal data in order to function. By using the site you are agreeing to this as outlined in our Privacy Notice and Terms of Use.