Self-assembly and structural-functional flexibility of oxygenic photosynthetic machineries: personal perspectives.
This short review, with a bit of historical aspect and a strong personal bias and emphases on open questions, is focusing on the (macro-)organization and structural-functional flexibilities of the photosynthetic apparatus of oxygenic photosynthetic organisms at different levels of the structural complexity-selected problems that have attracted most my attention in the past years and decades. These include (i) the anisotropic organization of the pigment-protein complexes and photosynthetic membranes-a basic organizing principle of living matter, which can, and probably should be adopted to intelligent materials; (ii) the organization of protein complexes into chiral macrodomains, large self-assembling highly organized but structurally flexible entities with unique spectroscopic fingerprints-structures, where, important, high-level regulatory functions appear to 'reside'; (iii) a novel, dissipation-assisted mechanism of structural changes, based on a thermo-optic effect: ultrafast thermal transients in the close vicinity of dissipation of unused excitation energy, which is capable of inducing elementary structural changes; it makes plants capable of responding to excess excitation with reaction rates proportional to the overexcitation above the light-saturation of photosynthesis; (iv) the 3D ultrastructure of the granum-stroma thylakoid membrane assembly and other multilamellar membrane systems, and their remodelings-associated with regulatory mechanisms; (v) the molecular organization and structural-functional plasticity of the main light-harvesting complex of plants, in relation to their crystal structure and different in vivo and in vitro states; and (vi) the enigmatic role of non-bilayer lipids and lipid phases in the bilayer thylakoid membrane-warranting its high protein content and contributing to its structural flexibility.
Győző
G
Garab
D016880:Anisotropy; D002942:Circular Dichroism / Q000379:methods*; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry* / Q000378:metabolism; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology; D045332:Photosystem II Protein Complex / Q000737:chemistry / Q000378:metabolism; D010860:Pigments, Biological / Q000737:chemistry; D020524:Thylakoids / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*
D045342:Light-Harvesting Protein Complexes; D008563:Membrane Lipids; D045332:Photosystem II Protein Complex; D010860:Pigments, Biological