Isolation and characterization of a Photosystem II complex from the red alga Cyanidium caldarium: association of cytochrome c-550 and a 12 kDa protein with the complex (original) (raw)
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Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1978
A Photosystem II (PS II) complex was purified from an acidophilic as well as a thermophilic red alga, Cyanidium caldarium. The purified PS II complex was essentially devoid of phycobiliproteins and other contaminating components, and showed a high oxygen-evolving activity of 2375 pmol O,/mg Chl per h using phenyl-p-benzoquinone as the electron acceptor. The expression of this high activity did not require addition of exogenous Ca*+, although EDTA reduced the activity by 40%. This effect of EDTA can be reversed not only by Ca*+ but also by Mgzf; a similar Mg *' effect has been observed in purified cyanobacterial PS II but not in higher plant PS II. Immunoblotting analysis indicated the presence of major intrinsic polypeptides commonly found in PS II from cyanobacteria and higher plants as well as the extrinsic 33 kDa protein. Antibodies against the extrinsic 23 and 17 kDa proteins of higher plant PS II, however, did not crossreact with any polypeptides in the purified PS II, indicating the absence of these proteins in the red alga. In contrast, two other extrinsic proteins of 17 and 12 kDa were present in the red algal PS II; they were released by 1 M Tris or Urea/NaCl treatment but not by 1 M NaCl. The 17 kDa polypeptide was identified to be cytochrome c-550 from heme-staining, immunoblot analysis and N-terminal amino acid sequencing, and the 12 kDa protein was found to be homologous to the 12 kDa extrinsic protein of cyanobacterial PS II from its N-terminal sequence. These results indicate that PS II from the red alga is closely related to PS II from cyanobacteria rather than to that from higher plants, and that the replacement of PS II extrinsic cytochrome c-550 and the 12 kDa protein by the extrinsic 23 and 17 kDa proteins occurred during evolution from red algae to green algae and higher plants. OOO5-2728/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDlOOO5-2728(95)00122-O I. Enami et al.
European Journal of Biochemistry, 1977
A membrane-bound cytochrome resembling higher plant cytochrome f in many respects has been extracted from the algae Chlamydomonas, Euglena and Anacystis, and partially purified. The spectra of the cytochromes from Chlamydomonas and Euglena are virtually identical to that of parsley cytochrome & with a-band maxima near 554 nm, very asymmetrical fl-bands, and y-band maxima at 421 nm. The cytochrome from Anacystis had c1 and y-bands both shifted to slightly longer wavelengths. The redox potential of the cytochrome from Chlamydomonas was determined as + 350 mV, and its minimum molecular weight in sodium dodecyl sulphate as 31 000. The cytochrome from Euglena showed a rate of reaction with higher plant plastocyanin at least 100 times that of the soluble Euglena cytochrome c-552, and was unaffected by Euglena cytochrome c-552 antiserum.
Biochimica et Biophysica Acta (BBA) - Bioenergetics, 2007
Structure and organisation of Photosystem I and Photosystem II isolated from red alga Cyanidium caldarium was determined by electron microscopy and single particle image analysis. The overall structure of Photosystem II was found to be similar to that known from cyanobacteria. The location of additional 20 kDa (PsbQ′) extrinsic protein that forms part of the oxygen evolving complex was suggested to be in the vicinity of cytochrome c-550 (PsbV) and the 12 kDa (PsbU) protein. Photosystem I was determined as a monomeric unit consisting of PsaA/B core complex with varying amounts of antenna subunits attached. The number of these subunits was seen to be dependent on the light conditions used during cell cultivation. The role of PsaH and PsaG proteins of Photosystem I in trimerisation and antennae complexes binding is discussed.
Biochimica et Biophysica Acta (BBA) - Bioenergetics, 2012
A unique regulation of the expression of the psbA, psbD, and psbE genes, encoding the D1, D2 and cytochrome b559 subunits of the Photosystem II complex in the chlorophyll d containing cyanobacterium Acaryochloris marina a b s t r a c t Photosynthetic electron transport, chromatic photoacclimation and expression of the genes encoding the D1, D2, and cytochrome b559 subunits of the Photosystem II complex were studied in the chlorophyll d containing cyanobacterium Acaryochloris marina MBIC11017 under various environmental conditions. During oxygen deprivation and inhibition of photosynthetic electron transport by dibromothymoquinone the psbA1 gene encoding a D1′ isoform was induced. All of the three psbA and one of the three psbD (psbD2) genes, encoding two different isoforms of the D1 and the abundant isoform of the D2 proteins, respectively were induced under exposure to UV-B radiation and high intensity visible light. Under far red light the amount of Photosystem II complexes increased, and expression of the psbE2 gene encoding the alpha-subunit of cytochrome b559 was enhanced. However, the psbF and psbE1 genes encoding the beta-and another isoform of alpha-cytochrome b559, respectively remained lowly expressed under all conditions. Far red light also induced the psbD3 gene encoding a D2′ isoform whose primary structure is different from the abundant D2 isoform. psbD3 was also induced under low intensity visible light, when chromatic photoacclimation was indicated by a red-shifted absorption of chlorophyll d. Our results show that differential expression of multigene families encoding different isoforms of D1 and D2 plays an important role in the acclimation of A. marina to contrasting environmental conditions. Moreover, the disproportionate quantity of transcripts of the alpha and beta subunits of cytochrome b559 implies the existence of an alpha-alpha homodimer organization of cytochrome b559 in Photosystem II complexes.
Photosynthesis Research, 2002
The Mn4 cluster of PS II advances through a series of oxidation states (S states) that catalyze the breakdown of water to dioxygen in the oxygen-evolving complex. The present study describes the engineering and purification of highly active PS II complexes from mesophilic His-tagged Synechocystis PCC 6803 and purification of PS II core complexes from thermophilic wild-type Synechococcus lividus with high levels of the extrinsic polypeptide, cytochrome c 550. The g = 4.1 S2 state EPR signal, previously not characterized in untreated cyanobacterial PS II, is detected in high yields in these PS II preparations. We present a complete characterization of the g = 4.1 state in cyanobacterial His-tagged Synechocystis PCC 6803 PS II and S. lividus PS II. Also presented are a determination of the stoichiometry of cytochrome c 550 bound to His-tagged Synechocystis PCC 6803 PS II and analytical ultracentrifugation results which indicate that cytochrome c 550 is a monomer in solution. The temperature-dependent multiline to g = 4.1 EPR signal conversion observed for the S2 state in cyanobacterial PS II with high cytochrome c 550 content is very similar to that previously found for spinach PS II. In spinach PS II, the formation of the S2 state g = 4.1 EPR signal has been found to correlate with the binding of the extrinsic 17 and 23 kDa polypeptides. The finding of a similar correlation in cyanobacterial PS II with the binding of cytochrome c 550 suggests a functional homology between cytochrome c 550 and the 17 and 23 kDa extrinsic proteins of spinach PS II.
European Journal of Biochemistry, 1995
Photosystem I and I1 core complexes were resolved in a single step from the thylakoid menibrane of Synechot.y.rti.v sp. PCC 6803 by using a mild solubilization procedure in dodecyl /~-t)-maltoside arid Deriphat/PAGE. For each photosystem, two green bands were obtained containing oligomcric and monomeric forms of the core complexes of either photosystem. The oligoniers are likcly to be trimei-s i n the case of photosystem T and dinicrs for photosystem 11, The absorption spectra, polypeptide and pigment composition of green bands corresponding to cither photosystem I or photosyslem TI wci-e identical for monomeric and oligomeric forms. Thc cytochromc b-559 content of photosystem I1 was evalualed to bc one cytochrome h-S59/reaction centre both in the monomeric and diineric forms. Two new I5-kDa and 22-kDa carotenoid-binding proteins were isolated and their polypeptides purified to homogeneity. Keywords: photosystem I ; photosystem 11; pigment-protein complexes: cyanobacteria.
Cytochrome c550 in the Cyanobacterium Thermosynechococcus elongatus
Journal of Biological Chemistry, 2004
Cytochrome c 550 is one of the extrinsic Photosystem II subunits in cyanobacteria and red algae. To study the possible role of the heme of the cytochrome c 550 we constructed two mutants of Thermosynechococcus elongatus in which the residue His-92, the sixth ligand of the heme, was replaced by a Met or a Cys in order to modify the redox properties of the heme. The H92M and H92C mutations changed the midpoint redox potential of the heme in the isolated cytochrome by ؉125 mV and ؊30 mV, respectively, compared with the wild type. The binding-induced increase of the redox potential observed in the wild type and the H92C mutant was absent in the H92M mutant. Both modified cytochromes were more easily detachable from the Photosystem II compared with the wild type. The Photosystem II activity in cells was not modified by the mutations suggesting that the redox potential of the cytochrome c 550 is not important for Photosystem II activity under normal growth conditions. A mutant lacking the cytochrome c 550 was also constructed. It showed a lowered affinity for Cl ؊ and Ca 2؉ as reported earlier for the cytochrome c 550-less Synechocystis 6803 mutant, but it showed a shorter lived S 2 Q B Ϫ state, rather than a stabilized S 2 state and rapid deactivation of the enzyme in the dark, which were characteristic of the Synechocystis mutant. It is suggested that the latter effects may be caused by loss (or weaker binding) of the other extrinsic proteins rather than a direct effect of the absence of the cytochrome c 550. Cytochrome c 550 (cyt c 550), 1 present in cyanobacteria and red algae, was first discovered by Holton and Myers (1) as a soluble monoheme c-type cytochrome. The cyt c 550 has a molecular mass of about 15 kDa, His/His coordination and a very low redox potential around Ϫ260 mV (for review see Ref. 2). Shen et al. (3-5) showed that cyt c 550 is stoichiometrically bound to the Photosystem II (PS II), activates oxygen evolving activity and allows the binding of the 12 kDa protein, another extrinsic
Higher Plant and Cyanobacterial Photosystem I: Connected Cytochrome Pathways
2016
Oxygenic photosynthesis is the principal converter of sunlight into chemical energy on earth. The conversion of solar energy is catalyzed by four multi-subunit membrane protein complexes: photosystem I (PSI), photosystem II (PSII), the cytochrome b6-f complex (cytb6f) and ATP-synthase (FOF1). These protein complexes are connected by soluble electron carriers that are vital not only for the proper function of ATP and NADPH production but also to render the system highly efficient in different organisms and various environments, some of which are quite harsh. While the main fabric of the membrane complexes is highly conserved, their surfaces and interaction with the soluble factors provide the specificity and fine regulation of the operating system. One of the prime examples for this phenomenon is the cyanobacterial photosynthetic electron transport chain that is situated alongside with respiratory complexes, yet it stays unique by virtue of the interacting soluble components. Cyanoba...