Cryptomonad biliproteins: Bilin types and locations

Wedemayer, Gary J.; Kidd, D G; Glazer, Alexander N.

doi:10.1007/bf00041006

Cited by 46 publications

(31 citation statements)

References 23 publications

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“…Consequently, the two β-DiCys-50,61 chromophores are not in physical contact, but separated by ~20 Å by a waterfilled opening. 28 The absence of a pair of strongly coupled chromophores positioned in the core of the PE555 complex, a structural feature common to all the other studied PBS, seems to be confirmed also by previous studies 29 confirming that in the specific case of PE555 the terminal energy acceptor bilins are the DVB residing at the β-DiCys-50,61 positions. It is thus unlikely that these bilins can form an excitonic dimer like in the other PBS.…”

Section: Two-dimensional Photon Echo Spectroscopy (2dpe)supporting

confidence: 79%

Differences among coherent dynamics in evolutionary related light-harvesting complexes: evidence for subtle quantum-mechanical strategies for energy transfer optimization

Collini

2012

SPIE Proceedings

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In this work we exploit two-dimensional photon echo experiments (2DPE) to observe quantum coherence dynamics in energy transfer in light-harvesting proteins isolated from marine cryptophyte algae. Previous data, recorded on two complexes (PC645 and PE545) at room temperature, revealed exceptionally long lasting oscillations with distinct correlations and anti-correlations even at ambient temperature. These observations provided compelling evidence for quantum-coherent sharing of electronic excitation across the 5-nm-wide proteins under biologically relevant conditions, suggesting that distant molecules within the photosynthetic proteins are 'wired' together by quantum coherence for more efficient light-harvesting. In this work measurements performed on a different evolutionary related complex (PE555) at two excitation wavelengths are presented. The new results highlight different lifetimes for electronic coherences. Although preliminary, these evidences can be tentatively interpreted considering the difference in the protein structures.

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Section: Two-dimensional Photon Echo Spectroscopy (2dpe)supporting

confidence: 79%

Differences among coherent dynamics in evolutionary related light-harvesting complexes: evidence for subtle quantum-mechanical strategies for energy transfer optimization

Collini

2012

SPIE Proceedings

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“…More recently, a lyase/isomerase from the cyanobacterium Mastigocladus laminosus was described that is involved in both the isomerization of PCB to phycoviolobilin and its covalent attachment to apo-␣-phycoerythrocyanin (Zhao et al, 2000). On the basis of these results and the diversity of bilin isomers found in phycobiliproteins from marine cyanobacteria, cryptomonads, and oxyphotobacteria (Ong and Glazer, 1991;Hess et al, 1996;Wedemayer et al, 1996), it is likely that numerous bilin isomerases are present in these oxygen-evolving photosynthetic organisms.…”

Section: Phycobilin Isomerases: Are They Necessary?mentioning

confidence: 90%

Functional Genomic Analysis of the HY2 Family of Ferredoxin-Dependent Bilin Reductases from Oxygenic Photosynthetic Organisms

et al. 2001

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Phytobilins are linear tetrapyrrole precursors of the light-harvesting prosthetic groups of the phytochrome photoreceptors of plants and the phycobiliprotein photosynthetic antennae of cyanobacteria, red algae, and cryptomonads. Previous biochemical studies have established that phytobilins are synthesized from heme via the intermediacy of biliverdin IX ␣ (BV), which is reduced subsequently by ferredoxin-dependent bilin reductases with different double-bond specificities. By exploiting the sequence of phytochromobilin synthase (HY2) of Arabidopsis, an enzyme that catalyzes the ferredoxin-dependent conversion of BV to the phytochrome chromophore precursor phytochromobilin, genes encoding putative bilin reductases were identified in the genomes of various cyanobacteria, oxyphotobacteria, and plants. Phylogenetic analyses resolved four classes of HY2 -related genes, one of which encodes red chlorophyll catabolite reductases, which are bilin reductases involved in chlorophyll catabolism in plants. To test the catalytic activities of these putative enzymes, representative HY2 -related genes from each class were amplified by the polymerase chain reaction and expressed in Escherichia coli . Using a coupled apophytochrome assembly assay and HPLC analysis, we examined the ability of the recombinant proteins to catalyze the ferredoxin-dependent reduction of BV to phytobilins. These investigations defined three new classes of bilin reductases with distinct substrate/product specificities that are involved in the biosynthesis of the phycobiliprotein chromophore precursors phycoerythrobilin and phycocyanobilin. Implications of these results are discussed with regard to the pathways of phytobilin biosynthesis and their evolution. INTRODUCTIONPhytobilins are linear tetrapyrrole molecules synthesized by plants, algae, and cyanobacteria that function as the direct precursors of the chromophores of the light-harvesting phycobiliproteins and of the photoreceptor phytochrome (Beale, 1993;Hughes and Lamparter, 1999). The pathways of phytobilin biosynthesis have been elucidated by biochemical fractionation of plant and algal extracts, by overcoming a blocked step with exogenous putative intermediates, and by analysis of linear tetrapyrrole-deficient mutants (Beale and Cornejo, 1991a, 1991b, 1991cTerry et al., 1993). These studies indicate that the biosynthesis of phytobilins shares common intermediates with heme and chlorophyll biosynthetic pathways to the level of protoporphyrin IX, at which point the latter two pathways diverge by metalation with iron or magnesium (Beale, 1993). Phytobilins are derived from heme, which is converted to biliverdin IX ␣ (BV), the first committed intermediate in their biosynthesis. In red algae, cyanobacteria, and plants, this interconversion is accomplished by ferredoxin-dependent heme oxygenases that are related in sequence to the mammalian heme oxygenase (Cornejo et al., 1998;Davis et al., 1999;Muramoto et al., 1999). Although they catalyze the same reaction, mammalian heme oxygenases use an NADPH-d...

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“…The C-would signify that the biliprotein was isolated from a cyanobacterium. Cryptomonad biliproteins have many different bilins (Wedemayer et al 1996). It is sometimes confusing that the bilins have the same name for both the free and the covalently attached bilin.…”

Section: William a Samsonoff · Robert Maccollmentioning

confidence: 99%

Biliproteins and phycobilisomes from cyanobacteria and red algae at the extremes of habitat

Samsonoff

MacColl

2001

Archives of Microbiology

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This review considers the properties of biliproteins from cyanobacteria and red algae that grow in extreme habitats. Three situations are presented: cyanobacteria that grow at high temperatures; a red alga that grows in acidic conditions at high temperature; and an Antarctic red alga that grows in the cold in dim light conditions. In particular, the properties of their biliproteins are compared to those from organisms from more usual environments. C-phycocyanins from two cyanobacteria able to grow at high temperatures are found to differ in their stabilities when compared to C-phycocyanin from mesophilic algae. They differ in opposite ways, however. One is more stable to dissociation than the mesophilic protein, and the other is more easily dissociated at low temperatures. The thermophilic proteins resist thermal denaturation much better than the mesophilic proteins. The most thermophilic cyanobacterium has a C-phycocyanin with a unique blue-shifted absorption maximum which does not appear to be part of the adaptation of the cyanobacterium to high temperature. The C-phycocyanin from the high-temperature red alga is able to resist dissociation better than mesophilic C-phycocyanins. Electron micrographs show the phycobilisomes of these algae. The Antarctic alga grows under ice at some distance down the water column. Its R-phycoerythrin has a novel absorption spectrum that gives the alga an improved ability to harvest blue light. This may enhance its survival in its light-deprived habitat.

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Cryptomonad biliproteins: Bilin types and locations

Cited by 46 publications

References 23 publications

Differences among coherent dynamics in evolutionary related light-harvesting complexes: evidence for subtle quantum-mechanical strategies for energy transfer optimization

Differences among coherent dynamics in evolutionary related light-harvesting complexes: evidence for subtle quantum-mechanical strategies for energy transfer optimization

Functional Genomic Analysis of the HY2 Family of Ferredoxin-Dependent Bilin Reductases from Oxygenic Photosynthetic Organisms

Biliproteins and phycobilisomes from cyanobacteria and red algae at the extremes of habitat

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