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Structural model of a tricylindrical hemidiscoidal phycobilisome (2, 3). The three sky blue circles represent the tricylindrical core APC, and two bottom cylinders attach to the thylakoid membrane (grey rectangle) with LCM. Six rods are arranged by PC (blue circle), and PE (red circle), and attached FNR (grass green circle) with LR from inner to outer part. LRC is the linker between core and rod. All linkers are represented by yellow discs located in each rod.

Structural model of a tricylindrical hemidiscoidal phycobilisome (2, 3). The three sky blue circles represent the tricylindrical core APC, and two bottom cylinders attach to the thylakoid membrane (grey rectangle) with LCM. Six rods are arranged by PC (blue circle), and PE (red circle), and attached FNR (grass green circle) with LR from inner to outer part. LRC is the linker between core and rod. All linkers are represented by yellow discs located in each rod.

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Cyanobacteria are the oldest life form making important contributions to global CO2 fixation on the Earth. Phycobilisomes (PBSs) are the major light harvesting systems of most cyanobacteria species. Recent availability of the whole genome database of cyanobacteria provides us a global and further view on the complex structural PBSs. A PBSs linker f...

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... are prominent constituents of marine biosphere that account for a significant percentage of oceanic primary productivity, and are among the oldest life forms on the Earth capable of doing oxygenic photosynthesis about 3.5 billion years ago, which is similar to the process found in higher plants [1][2]. As the oldest and major light-harvesting antennae, PBSs are highly organized complexes of various PBPs and linker polypeptides ( Fig.1.), and are very diverse in structure and pigment composition in cyanobacteria, red algae, and the cryptomonads [3][4][5]. They function in light harvesting and energy migration toward photosystem II or I reaction centers in thylakoid membrane, except Gloeobacter violaceus PCC7421 (Gv) having no thylakoid membrane ...

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Citations

... The heterologous rod linker protein CpcC (33 kDa) from T. elongatus was expressed in both TeBACD and TeBAC strains. Both CpcC and CpcC1 connect the first two PC hexamers within the rod to the APC core (David et al., 2011;Guan et al., 2007;Ughy and Ajlani, 2004). A phylogenetic comparison showed that CpcC is more closely related to CpcC1 than CpcC2 ( Supplementary Fig. S2), which may explain why CpcC was not degraded in Synechocystis. ...
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... Cyanobacteria are the oldest form of Gram-negative photosynthetic bacteria, which carry out photosynthesis similar to higher plants (Guan et al. 2007). These micro-organisms have a wide range of pigments such as carotenoids, chlorophyll a and phycobiliproteins (PBPs). ...
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... Apt, Collier, and Grossman (1995) studied in depth the evolution of the PBPs by comparing PBP sequences. This study was expanded by more recent work about the evolution of linker proteins (Guan, Qin, Zhao, Zhang, & Tang, 2007;Shi, Qin, & Wang, 2011) and the PE evolution and diversification in marine Synechococcus (Everroad & Wood, 2012;Six et al., 2007;Ting, Rocap, King, & Chisholm, 2002) (see Fig. 3). ...
... The rod components seem to evolve through complex ways including gene duplication, lateral gene transfer and gene loss (see Everroad and Wood, 2012;Six et al., 2007;and references within). Rod linkers and rod-core linkers most probably co-evolved with these genes leading to modern PBS structures (Apt et al., 1995;Guan et al., 2007). The evolution from the ancestor heterodimer to the modern different PBPs brought an increased light-harvesting capacity by attaching a higher quantity and diversity of chromophores. ...
... For more extensive reviews about the evolution of phycobiliproteins, see Apt et al. (1995), Everroad and Wood (2012), Guan et al. (2007), Shi et al. (2011), Six et al. (2007, Ting et al. (2002), and Zhao and Qin (2006). ...
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... The sequential extraction of A-PC by membrane permeabilization method can be explained based on the structure of the phycobilisome (Fig. 6b). Phycobilisomes are protein complexes, made of stacks of chromophorylated proteins, the phycobiliproteins, anchored to thylakoid membranes [46]. Each phycobilisome consists of outwardly oriented rods made of stacked disks of phycocyanin connected to a core made of A-PC by 'linker' polypeptides, that is rod-core linker, corelinker and core-membrane linker [47]. ...
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... phycobilisome complex is generally composed of the allophycocyanin core and the protruding rods (composed of several hexameric CpcAB discs). These chromophoric components are interconnected by specific internal linker proteins and are attached to the thylakoid membrane (78). The terminal linker CpcD is located on the apical tip of the rods, and regulates the antennae length by preventing further elongation (79). ...
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... The sequential extraction of A-PC by membrane permeabilization method can be explained based on the structure of the phycobilisome (Fig. 6b). Phycobilisomes are protein complexes, made of stacks of chro- mophorylated proteins, the phycobiliproteins, anchored to thylakoid membranes [46]. Each phycobilisome consists of outwardly oriented rods made of stacked disks of phycocyanin connected to a core made of A-PC by 'linker' polypeptides, that is rod-core linker, core-linker and core-membrane linker [47]. ...
Preprint
Conventional extraction methods are able to extract only 50-60% of the total allophycocyanin (A-PC) present in a given biomass. One of the reasons is the resistance offered by the cell membrane for its disruption. The present study is aimed at screening different conventional methods and their combinations (to explore synergy) to arrive at the most suitable methodology for the primary extraction of A-PC from dry biomass of Arthrospira platensis. A synergistic effect was observed on employing ultrasonication in combination with other conventional methods. Ultrasonication with freezing and thawing resulted in the highest A-PC extraction efficiency of 93.11%. The problem of purification of A-PC when extracted along with c-phycocyanin (C-PC), due to same biochemical properties, could be overcome by carrying out ‘ultrasonication followed by sequential extraction employing freezing and thawing’. A-PC with an yield of 40% (devoid of C-PC) with a purity of 1.15 could be extracted, the highest reported till date during primary extraction itself.
... Cyanobacteria are a primitive group of Gram-negative photosynthetic prokaryotes that originated around 3.5 billion years ago (Guan et al., 2007). They are ubiquitously distributed throughout the Earth surface and play a distinguished role in natural ecosystems for the production of primary biomass (Häder et al., 2015). ...
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With the rise in developmental activities, a load of pollution in the environment has increased. Most of the water bodies remain polluted due to the wastewater released by agricultural, domestic and industrial activities. Treatment of wastewater by physical, chemical and biological approaches is implied in order to cope with this problem and discharge an apparently clean effluent into natural water bodies. Recently, for the biological treatment of wastewater micro-algae have gained importance since they are able to accumulate plant nutrients, heavy metals, pesticides, organic and inorganic toxic substances and radioactive matters in their bodies. Further, the biomass left after the treatment is used for biogas generation and bio-compost. Biological wastewater treatment systems with micro-algae are now widely accepted as effective and low-cost natural treatment systems for purification of wastewater. In this chapter, we highlight the role of micro-algae in the treatment and management of wastewater.