Functional assignment of chromophores and energy transfer in C phycocyanin isolated from the thermophilic cyanobacterium Mastigocladus laminosus

Mimuro, Mamoru; Füglistaller, Paul; Rümbeli, Robert; Zuber, Herbert

doi:10.1016/0005-2728(86)90037-x

Cited by 101 publications

(105 citation statements)

References 33 publications

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“…The fluorescence and polarization spectra (Fig. 1) are similar to those reported for the subunits of this pigment [16]. The polarization spectra of the a-subunit are rather independent of the excitation wavelength, a, fact which indicates that emission takes place from the excited chromophore only.…”

Section: Fluorescence Polarizationsupporting

confidence: 77%

Picosecond time-resolved fluorescence of phycobiliproteins: Subunits of phycocyanin from Mastigocladus laminosus

Fischer¹,

Gottstein²,

Scheer³

et al. 1990

Journal of Photochemistry and Photobiology B: Biology

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SummaryThe (Y-and &subunits of C-phycocyanin from Mastigocladus laminosus were prepared according to revised procedures. Both subunits are isolated as dimers, which can be dissociated into monomers with detergent mixtures. The fluorescence decay kinetics are similar for the respective monomers and dimers. In no case could they be fitted by only one (o-subunit) or two exponentials (P-subunit) which are predicted by theory for samples with a unique chromophore-protein arrangement containing one and two chromophores, respectively. It is suggested that there exists a heterogeneity among the chromophores of the subunits, which may persist in the highly aggregated complexes present in cyanobacterial antennas.

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Section: Fluorescence Polarizationsupporting

confidence: 77%

Picosecond time-resolved fluorescence of phycobiliproteins: Subunits of phycocyanin from Mastigocladus laminosus

Fischer¹,

Gottstein²,

Scheer³

et al. 1990

Journal of Photochemistry and Photobiology B: Biology

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“…The a subunit showed an absorption maximum at 643 nm with a shoulder at 570 nm. Its spectrum was very similar to the a chain of C-phycocyanin from M. laminosus and seemed to be characteristic for isolated phycocyanin n subunits with a single phycocyanobilin chromophore (Mimuro et al, 1986a). The p subunit exhibited absorption maxima at 562 nm and 642 nm characteristic for the presence of both a phycoerythrobilin and a phycocyanobilin chromophore as already shown (Ong and Glazer, 1987).…”

Section: Isolation and Characterisation Of The R-phycocyanin-i A And supporting

confidence: 71%

The complete amino acid sequence of R‐phycocyanin‐I α and β subunits from the red alga Porphyridium cruentum

Ducret¹,

Sidler²,

Frank³

et al. 1994

European Journal of Biochemistry

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We present here the complete primary structure of R-phycocyanin-I a and p subunits from the red alga Porphyridium cruentum. The a chain is composed of 162 amino acid residues (18049Da, calculated from sequence, including chromophore) and carries a phycocyanobilin pigment covalently linked to Cys84. The p chain contains 172 amino acids (19344Da, calculated from sequence, including chromophores) and carries a phycocyanobilin pigment covalently linked at Cys82 and a phycoerythrobilin pigment at Cys153. A y-N-methyl asparagine residue was also characterised at position ,872 similar to other phycobiliprotein , 6 subunits. R-phycocyanin-I from Porphyridium cruentum shares high sequence identity with C-phycocyanins (69 -83%), R-phycocyanins (66-70%) and in a less extent with phycoerythrocyanins (57-65%) from various sources.The presented phylogenetic trees are based on a comparison of all phycobiliprotein amino acid sequences known so far and confirm the clear affiliation of the R-phycocyanins in the phycocyanin family. In spite of their particular phycobilin pattern, they do not represent intermediate forms between the phycocyanin and the phycoerythrin family. Phycoerythrocyanin, a phycocyanin-related phycobiliprotein adapted to green light harvesting, is also shown to belong to the phycocyanin family. However, the phycoerythrocyanins diverge from phycocyanins in their different function and it is suggested that they should be assigned to a separate group within the phycocyanin family.Phycobilisomes represent the main accessory light-harvesting antenna of cyanobacteria and red algae (Cohen-Bazire and Bryant, 1982;Zuber, 1983Glazer, 1984Glazer, , 1985Gantt, 1988;Bryant, 1991; Sidler, 1994). Their major components, the phycobiliproteins, are constituted of a and p subunits (16-18 kDa and 18-20 kDa respectively) carrying one, two or three open-chain tetrapyrroles (bilins) per subunit as prosthetic groups. Both subunits are aggregated in vivo to heterotrimers (an3 or hexamers (anb. Electron microscopy and crystal structure analysis show that the trimer complex is the basic building block of the phycobilisome (Schirmer et al., 1985). The ap monomer aggregates in a disc-shaped complex with a diameter of 11 nm and a length of 3 nm. A hexamer is built up of two trimers stacked face-to-face (Schirmer et al., 1986). The formation of higher aggregatesCorrespondence to H.

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“…5). These spectra for individual subunits and the the, ax-1 combinations were similar to spectra for PC subunits and trimers from Mastigocladus laminiosus (18 Fig. 5a) showed that the precipitate fro'm the 16 a plus WT reaction was enriched for subunit (13/a molar ratio of 1.5), and the soluble material was enriched for the a subunit (a113 molar ratio of 0.5).…”

Section: Methodssupporting

confidence: 61%

Mutations that affect structure and assembly of light-harvesting proteins in the cyanobacterium Synechocystis sp. strain 6701

Anderson¹,

Rayner²,

Eiserling³

1987

J Bacteriol

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The unicellular cyanobacterium Synechocystis sp. strain 6701 was mutagenized with UV irradiation and screened for pigment changes that indicated genetic lesions involving the light-harvesting proteins of the phycobilisome. A previous examination of the pigment mutant UV16 showed an assembly defect in the phycocyanin component of the phycobilisome. Mutagenesis of UV16 produced an additional double mutant, UV16-40, with decreased phycoerythrin content. Phycocyanin and phycoerythrin were isolated from UV16-40 and compared with normal biliproteins. The results suggested that the UV16 mutation affected the a subunit of phycocyanin, while the phycoerythrin subunit from UV16-40 had lost one of its three chromophores. Characterization of the unassembled phycobilisome components in these mutants suggests that these strains will be useful for probing in vivo the regulated expression and assembly of phycobilisomes.Phycobilisomes are the light-harvesting structures of cyanobacteria and red algae. Composed of chromophoric biliproteins and nonchromophoric linker proteins, phycobilisomes are organized into two structural domains, the core and the rods (reviewed in reference 12). The core is associated with the thylakoid membrane and contains the allophycocyanin (AP) biliproteins. The rods are attached to the membrane-distal periphery of the core and, in the unicellular cyanobacterium Synechocystis sp. strain 6701, contain phycocyanin (PC) and phycoerythrin (PE) biliproteins and four linker proteins of 27, 30.5, 31.5, and 33.5 kilodaltons (kDa) (9, 12).UV irradiation has been used to obtain pigment mutants in strain 6701 (3). Preliminary characterization of a phycobilisome assembly mutant, UV16, demonstrated intact core substructures with little PC bound and soluble PC trimers that were free of linker proteins. The PE in UV16 assembled into rod substructures that contained the 31.5-and 30.5-kDa PE linker proteins and cosedimented with cores on a sucrose gradient (3). The UV16 strain was mutagenized to find a mutant that would eliminate PE contamination of cores. We obtained the mutant strain UV16-40 from a colony with lighter green pigmentation, indicating decreased PE relative to the parent strain, UV16. We examined relative biliprotein content, assembly of rod components, and the chromatic adaptation response (22) in the UV16 and UV16-40 strains. The defective PC and PE biliproteins were isolated from UV16-40 and compared with normal PC and PE from wildtype (WT) and UV16 strains. The resulting differences suggested the presence of structural lesions in the PC ax subunit of UV16 and the PE ,B subunit of UV16-40. MATERIALS AND METHODSStrains, media, and culture conditions. Synechocystis sp. strain 6701 (Pasteur Culture Collection) and mutant strains were grown in the medium and light conditions described previously (3). Strains UV16 and UV16-40 were obtained after UV mutagenesis (3) tively. The spontaneous reversion frequency for both mutants was not measured directly, but is less than lo-5. To assay chromatic adaptation respo...

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Functional assignment of chromophores and energy transfer in C phycocyanin isolated from the thermophilic cyanobacterium Mastigocladus laminosus

Cited by 101 publications

References 33 publications

Picosecond time-resolved fluorescence of phycobiliproteins: Subunits of phycocyanin from Mastigocladus laminosus

Picosecond time-resolved fluorescence of phycobiliproteins: Subunits of phycocyanin from Mastigocladus laminosus

The complete amino acid sequence of R‐phycocyanin‐I α and β subunits from the red alga Porphyridium cruentum

Mutations that affect structure and assembly of light-harvesting proteins in the cyanobacterium Synechocystis sp. strain 6701

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