Photosystem I of higher plants

RW Mansfield and MOW Evans (1986) UV optical difference spectrum associated with the reduction of electron acceptor A in photosystem I of higher plants. FEBS Lett 203 225-229... 

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. 

A. Kitmitto, A.O. Mustafa, A. Holzenburg, and R.C. Ford. 1998. Three-dimensional structure of higher plant photosystem I determined by electron crystallography J. Biol. Chem. 273 29592- 29599. (PubMed)... 

Photosystems-I thylakoids of higher plants and cyanobacteria are quite different from the bacterial system in that, for instance, besides having peripheral chlorophyll-protein complexes as antenna, there are also chlorophyll molecules functioning as the so-called core antenna complex in the reaction-center itself. A PS-1 core complex containing core antenna chlorophyll molecules was actually obtained as early... 

R Malkin (1987) Photosystem I. In J Barber (ed) The Light Reactions, pp 495-525. Elsevier JP Thornber, RJ Cogdell, P Chitnis, DT Morishige, GF Peter, SM G mez, S Anandan, S Preiss, BW Dreyfuss, A Lee, T Takeuchi and C Kerfeld (1994) Antenna pigment-protein complexes of higher plants and purple bacteria. In J Barber (ed) Advances in Molecular and Cell Biology, pp 55-118. JAI Press. 

Plastocyanin cycles between the Cu and Cu oxidation states, and transfers electrons from cytochrome / to the P700 component of photosystem I in the chloroplasts of higher plants and algae.The low molecular weight (10.5 kDa) and availability of detailed structural information have made this protein an attractive candidate for mechanistic studies, which, when taken together, point to two distinct surface binding sites (i.e., regions on the... 

Photosystem I (PS I) in higher plants can be conceived to be composed of two pigmented parts ... 

Electron Transport Between Photosystem I and Photosystem II Inhibitors. The interaction between PSI and PSII reaction centers (Fig. 1) depends on the thermodynamically favored transfer of electrons from low redox potential carriers to carriers of higher redox potential. This process serves to communicate reducing equivalents between the two photosystem complexes. Photosynthetic and respiratory membranes of both eukaryotes and prokaryotes contain stmctures that serve to oxidize low potential quinols while reducing high potential metaHoproteins (40). In plant thylakoid membranes, this complex is usually referred to as the cytochrome b /f complex, or plastoquinolplastocyanin oxidoreductase, which oxidizes plastoquinol reduced in PSII and reduces plastocyanin oxidized in PSI (25,41). Some diphenyl ethers, eg, 2,4-dinitrophenyl 2 -iodo-3 -methyl-4 -nitro-6 -isopropylphenyl ether [69311-70-2] (DNP-INT), and the quinone analogues,... 

Photosystem I (PS I) in the cyanobacterium Synechococcus elongatus is the first system of this type for which the structure has been solved in atomic detail. Although the bacterial photosystem differs slightly from the systems in higher plants, the structure provides valuable hints about the course of the light reactions in photosynthesis (see p. 128). The functioning of the photosystem is discussed in greater detail on p. 130. 

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