Chloroplasts protein complexes

Most thylakoid protein complexes described so far are composed of some polypeptide(s) encoded in the nucleus and other encoded in the chloroplast genome. The reductase/binding protein complex seems to be the only chloroplast protein complex whose two known components, reductase, which is synthesized in the cytoplasm as a precursor of 43 kDa (12) and its binding protein are encoded the nucleus, and they bind spontaneously in their nature form when Mg is present (2). 

In plant chloroplasts the newly synthesized L can bind to another chloroplast protein complex called large subunit binding protein (BP) (1). The intermediate steps of the assembly of higher plant Rubisco as well as the function of BP are still largely unknown. 

The amount of individual subunits of some of the chloroplast protein complexes was followed during greening of dark grown plants. Using the immunodecoration technique (Rott, Nelson 1981 Nelson 1983) it was found that many of the chloroplast protein complexes were... 

Kolubayev T, Geacintov N E, Paillotin G and Breton J 1985 Domain sizes in chloroplasts and chlorophyll-protein complexes probed by fluorescence yield quenching induced by singlet-triplet exciton annihilation Biochimica Biophys. Acta 808 66-76... 

The group of the be complexes comprises bci complexes in mitochondria and bacteria and bef complexes in chloroplasts. These complexes are multisubunit membrane proteins containing four redox centers in three subunits cytochrome b (cytochrome be in bef complexes) comprising two heme b centers in a transmembrane arrangement, cyto-... 

The carotenoids are located in photosynthetic pigment-protein complexes (PPCs) in the thylakoid membranes (Young, 1993), with minor amounts in the chloroplast envelope (Joyard et al, 1991) and the envelope of amyloplasts (Fishwick and Wright, 1980). In all plastid envelope membranes, violaxanthin is the major carotenoid. Carotenes are also found in plastoglobuli (Lichtenthaler and Peveling, 1966). 

Cohen, Y., S. Yalovsky, and R. Nechushtai. 1995. Integration and assembly of photosynthetic protein complexes in chloroplast thylakoid membranes. Biochim. Biophys. Acta 1241 1-30. 

Horton, R, Ruban, A. V., Rees, D., Rascal, A. A., Noctor, G., and Young, A. J. 1991. Control of the light-harvesting function of chloroplast membranes by aggregation of the LHCII chlorophyll protein complex. Eebs Lett. 292 1-4. 

J.P. Thomber, J.C. Stewart, M.W.C. Hatton and J.L. Bailey, Studies on the nature of chloroplast lamellae, II, Chemical composition and further physical properties of two chlorophyll-protein complexes, Biochemistry 6 (1967) 2006-2014. 

Andersson, B. and Anderson J.M. 1980. Lateral heterogeneity in the distribution of chlorophyll-protein complexes of the thylakoid membranes of spinach chloroplasts. Biochim. Biophys. Acta 593.427-440. 

Machold, O. andMeisterA. 1978. Resolution of the light harvesting chloro-phyll-a/b protein of Viciafaba chloroplasts into two different chloro-phyll-protein complexes. Biochim. Biophys. Acta 546.472 180. 

The values of A,max for Chi a in vivo result from interactions between a chlorophyll molecule and the surrounding molecules, such as the proteins and the lipids in the chloroplast lamellar membranes (Fig. 1-10) as well as adjacent water molecules. Indeed, all Chi a molecules are associated with proteins in chlorophyll-protein complexes. Hydrophobic interactions among... 

Carotenoids involved in photosynthesis are bound to and help stabilize chlorophyll-protein complexes, of which various types occur in the lamellar membranes of chloroplasts (Fig. 1-10). Carotenoids also are found in organelles known as chromoplasts, which are about the size of chloroplasts and are often derived from them. For instance, lycopene (red) is in tomato fruit chromoplasts, and a- and pi-carotenes (orange) occur in carrot root chromoplasts. A great diversity of carotenoids occurs in the chromoplasts of flower petals, which is important for attracting pollinators, and fruits, which aids in seed dispersal by attracting other animals. 

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