Photosystem II of higher plants

Thomber JP, Peter GF, Chitnis PR, Nechushtai R and Vainstein A. (1988). The light-harvesting complex of photosystem II of higher plants. In Stevens SE Jr, Bryant DA (eds), Light-energy Transduction in Photosynthesis Higher Plant and Bacterial Models, pp. 137-154 The American Society of Plant Physiologists, Rockville, Maryland. 

AG Voikov (1986) The molecular mechanism of functioning of photosystem II in higher plants A hypothesis. Photobiochem Photobiophys 11 1-7... 

In Photosystem II (PS II) of higher plants there are three extrinsic proteins with apparent molecular masses of 33, 24, and 16 kDa which have been shown to be closely related to photosynthetic oxygen evolution. All three proteins are located at the inner side of PS II complex (1) and can be removed by various washing procedures, usually with concomittant release of manganese. 

Photosystem II (PS II) of higher plant possess unique properties with respect to function, organization and protein turnover. It is a multisubunit protein complex which Is composed of at least 20 different polypeptides (1). The two reaction center polypeptides, designated D1 and D2, appear to carry all the redox components necessary for the primary photochemistry of PS II (2) and possibly also the Mn (3). The great majority of the PS II units is located in the appres-sed thylakold regions in association with its chlorophyll a/b antenna (4). PS II has a central catalytic role, but It also plays a central role In the long and short term acclimation of the photosynthetic apparatus. It Is also the target for the photoinhibition process which leads to Impaired electron transport capacity and the subsequent breakdown of the two reaction center subunits. In particular the Dl-protein. 

The plastocyanins are found in plant chloroplasts and other photosynthetic organisms, and act as membrane-bound electron carriers between photosystems II and I in the photosynthetic pathway of higher plants, green algae and some blue-green algae. 

Bialek-Bylka GE, Sakano Y, MizoguchiT, ShimamuraT, Phillip D, Koyama Y and Young AJ (1998a) Central-cis isomers of lutein found in the major light-harvesting complex of Photosystem II (LHC Ilb) of higher plants. Photosynth Res 56 255-264... 

Peter GF and Thornber P (1991) Biochemical composition and organisation of higher plant Photosystem II light harvesting proteins. J Biol Chem 266 16745-16754... 

Hankamer B, Morris EP, Nield J et al. Three-dimensional structure of photosystem II core dimer of higher plants determined by electron microscopy. J Struct Biol 2001 13 262-269. 

Prolonged illumination of higher plants with intense visible light leads to photoinhibition as observed by diminution of O2 evolution and electron transport rate through photosystem II (PS II) and by a decrease of variable fluorescence yield (for review see Ref. 1 and 2). The molecular mechanism of photoinhibition is not yet clear and there is still some discussion about the exact site(s) of the primary events. Most authors localized inhibition within the PS II reaction center or at the Qg-binding site. In addition for chloroplats with already inhibited oxygen evolution capacity, the involvement of PS II donor side components has been reported. 

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