Primary Processes of Photosynthesis: Structural and Functional Aspects

Subunit positioning and transmembrane helix organisation in the core dimer of photosystem II

“…Con¢rmation of this arrangement has now come from the X-ray di¡raction analysis of the cyanobacterial RC (see Fig. 3B) [3] and its implications have been discussed in a recent paper [28]. The X-ray structure showed that two chl molecules, equivalent to the accessory bacteriochlorophylls of the bacterial RC, are tilted at about 30³ to the membrane plane while the chls corresponding to the special pair are positioned vertical to the membrane plane [3].…”

Structure and Function of Light‐harvesting Complexes and Their Polypeptides

“…Studies in recent years have shown that a series of Chl aiChl b protein complexes with light-harvesting and energy transfer function are present not only in PS 11, but also in PS I, proximal to the RC (See reviews: Thornber ef al., 1979;Barber, 1979;Cogdell, 1983;Glazer, 1983). Studies also suggested, as for photosynthetic bacteria, different types of antenna complexes, some in contact with the RC, others more distant.…”

“…In the course of these it was generally admitted that complete understanding of the function of these pigment-protein complexes can only be achieved with detailed knowledge of their structure and molecular organization. The tendency to concentrate increasingly on the biochemical characterization and structure analysis of these complexes, which already appeared in earlier reviews of these series (Cogdell and Valentine, 1983;MacColl, 1982;Barber, 1979;Thornber et al, 1979), has become yet more marked in recent years. The detailed biochemical analysis also allowed a better identification of the various pigment protein complexes, which is essential for their isolation.…”

Alternative Fast and Slow Primary Charge‐Separation Pathways in Photosystem II

“…Photosystem‐II (PSII) is a key multi‐subunit protein complex of the photosynthetic chain, which converts the energy derived from sunlight into electrochemical potential required for catalyzing water oxidation and plastoquinone reduction [1–3] . The reaction centre (RC) of PSII accepts excitation energy from external light‐harvesting complexes and the internal CP43 and CP47 antennae to perform charge separation with near‐unity quantum efficiency [1, 4] . The RC of PSII consists of four Chlorophyll a (central pair P D1 P D2 or “special pair” (SP), and “accessory” Chl D1 and Chl D2 ) and two Pheophytin a pigments (Pheo D1 and Pheo D2 ), arranged symmetrically along the D1 and D2 core polypeptides (see Figure 1 A,B).…”