| conserved relationship between psbh and petbd genes: presence of a shared upstream element in prochlorothrix hollandica. | prochlorophytes are an unusual group of prokaryotic oxygenic photoautotrophs that morphologically appear to bridge the gap between cyanobacteria and the chloroplasts of eukaryotic plants. molecular data place this group evolutionarily within the cyanobacteria, but they have a photosynthetic apparatus that is very similar to that found in chloroplasts. we have sequenced from the prochlorophyte prochlorothrix hollandica a set of genes (psbb, psbh, petb and petd) that has a conserved organization i ... | 1992 | 1623188 |
| multiple evolutionary origins of prochlorophytes, the chlorophyll b-containing prokaryotes. | prochlorophytes are prokaryotes that carry out oxygenic photosynthesis using chlorophylls a and b, but lack phycobiliproteins as light-harvesting pigments. these characteristics distinguish them from cyanobacteria, which contain phycobiliproteins, but no chlorophyll b. three prochlorophyte genera have been described: prochloron, prochlorothrix and prochlorococcus. the prochlorophytes share their pigment characteristics with green plant and euglenoid chloroplasts, which has led to a debate on whe ... | 1992 | 1731224 |
| multiple evolutionary origins of prochlorophytes within the cyanobacterial radiation. | the taxonomic group prochlorales (lewin 1977) burger-wiersma, stal and mur 1989 was established to accommodate a set of prokaryotic oxygenic phototrophs which, like plant, green algal and euglenoid chloroplasts, contain chlorophyll b instead of phycobiliproteins. prochlorophytes were originally proposed (with concomitant scepticism) to be a monophyletic group sharing a common ancestry with these 'green' chloroplasts. results from molecular sequence phylogenies, however, have suggested that proch ... | 1992 | 1731225 |
| nucleotide sequence of psbb from prochlorothrix hollandica. | | 1991 | 1840692 |
| evidence for multiple xenogenous origins of plastids: comparison of psba-genes with a xanthophyte sequence. | when only plastidic features are considered, it is difficult to distinguish between monophyletic and polyphyletic xenogenous origins of plastids. we suggest that a direct comparison of nuclear and plastidic sequence-similarity pattern will help to solve this problem. the d1 amino acid sequence of six major groups of photosynthetic eukaryotes and of the two groups of photosynthetic prokaryotes are now available, including the psba-gene product from bumilleriopsis filiformis, which is the first mo ... | 1991 | 1879002 |
| sequence analysis and phylogenetic reconstruction of the genes encoding the large and small subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase from the chlorophyll b-containing prokaryote prochlorothrix hollandica. | prochlorophytes similar to prochloron sp. and prochlorothrix hollandica have been suggested as possible progenitors of the plastids of green algae and land plants because they are prokaryotic organisms that possess chlorophyll b (chl b). we have sequenced the prochlorothrix genes encoding the large and small subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase(rubisco), rbcl and rbcs, for comparison with those of other taxa to assess the phylogenetic relationship of this species. length d ... | 1991 | 1904095 |
| structural similarities between psba genes from red and brown algae. | the single copy psba genes from the multicellular red alga antithamnion spec. and the brown alga ectocarpus siliculosus have been cloned and sequenced and monocistronic transcripts have been detected. both genes contain an insertion of 21 bp at the 3' end which was also found in cyanobacteria and which is absent in chloroplasts and the chlorophyll b-containing prochlorophyte prochlorothrix hollandica. these findings are in agreement with the hypothesis of a polyphyletic origin of plastids. plast ... | 1991 | 1934114 |
| immunological characterization of the prochlorothrix hollandica and prochloron sp. chlorophyll a/b antenna proteins. | polyclonal antibodies were prepared against the major antenna chlorophyll (chl) a/b-binding protein from the prokaryote prochlorothrix hollandica (burger-wiersma et al. (1986) nature (lond.) 320, 262-264). immunoblotting experiments on triton x-114 phase-partitioned p. hollandica thylakoids revealed that the antibody recognizes intrinsic membrane polypeptides of 33 and 30 kda, and immunocytochemistry of p. hollandica thin sections showed that the antibody preferentially decorates the thylakoid. ... | 1990 | 2184090 |
| the ribulose bisphosphate carboxylase/oxygenase of prochlorothrix hollandica: purification, subunit structure and partial n-terminal sequence analysis of the large subunit. | ribulose bisphosphate carboxylase/oxygenase was purified to apparent homogeneity from the carboxysomes of prochlorothrix hollandica. the mw of the native enzyme was estimated to be 560,000 dalton, comprising large subunits (lsu) of 57,000 dalton and small subunits (ssu) of 13,000, probably in an 8lsu8ssu quaternary structure. enzyme activity was maximal at ph 8.0 at 30 degrees c. the requirement of activity for mg2+ could not be replaced by mn2+. co2+, ca2+ or cu2+. amino acid n-terminal sequenc ... | 1990 | 2282113 |
| enzymatic conversion of glutamate to delta-aminolevulinic acid in soluble extracts of euglena gracilis. | glutamate was converted to the chlorophyll and heme precursor delta-aminolevulinic acid in soluble extracts of euglena gracilis. delta-aminolevulinic acid-forming activity depended on the presence of native enzyme, glutamate, atp, mg2+, nadph or nadh, and rna. the requirement for reduced pyridine nucleotide was observed only if, prior to incubation, the enzyme extract was filtered through activated carbon to remove firmly bound reductant. dithiothreitol was also required for activity after carbo ... | 1987 | 2442164 |
| transformation of glutamate to delta-aminolevulinic acid by soluble extracts of synechocystis sp. pcc 6803 and other oxygenic prokaryotes. | delta-aminolevulinic acid is the first committed precursor in the biosynthesis of hemes, phycobilins, and chlorophylls. plants and algae synthesize delta-aminolevulinic acid from glutamate via an rna-dependent 5-carbon pathway. previous reports demonstrated that cyanobacteria form delta-aminolevulinic acid from glutamate in vivo. we now report the direct measurement of this activity in vitro. three oxygenic prokaryotes were examined, the unicellular cyanobacteria synechocystis sp. pcc 6803 and s ... | 1988 | 2454230 |
| lambda zap: improved strategies for expression library construction and use. | a strategy is presented for the efficient construction of lambda zap genomic expression libraries. procedures are described for the evaluation of the status of vector dna at each stage of library construction to facilitate troubleshooting. ligation of lambda zap cohesive ends and preparation of the multiple cloning site were verified by restriction enzyme digestion of vector dna. sonication was a rapid way of producing random chromosomal fragments of a size range ideal for expression library con ... | 1989 | 2523297 |
| psba genes indicate common ancestry of prochlorophytes and chloroplasts. | it has long been suspected that chloroplasts evolved after an endosymbiotic event involving a photosynthetic prokaryote, presumably a cyanobacterium, and a eukaryotic organism. recent studies have provided strong evidence about the cyanobacterial nature of chloroplasts. since the discovery of prochlorophytes, oxygen-evolving photosynthetic prokaryotes containing chlorophyll a and chlorophyll b and lacking phycobiliproteins, there has been speculation that these represent evolutionary intermediat ... | 1989 | 2643058 |
| the relationship of a prochlorophyte prochlorothrix hollandica to green chloroplasts. | it is generally accepted that chloroplasts arose from one or more endosymbiotic events between an ancestral cyanobacterium and a eukaryote. such an origin fits well in the case of the chloroplasts of rhodophytes that, like cyanobacteria, contain chlorophyll a and phycobilin pigments. the green chloroplasts from higher plants, green algae, and euglenoids however, contain chlorophyll b as well as chlorophyll a, and lack phycobilins. consequently, it has been suggested that they arose independently ... | 1989 | 2911389 |
| peptidoglycan-polysaccharide complex in the cell wall of the filamentous prochlorophyte prochlorothrix hollandica. | a peptidoglycan-polysaccharide complex composed of n-acetylglucosamine, n-acetylmuramic acid, muramic acid 6-phosphate, l-alanine, d-alanine, d-glutamic acid, meso-diaminopimelic acid, n-acetylmannosamine, mannose, galactose, glucose, and phosphate was isolated from cell walls of the filamentous prochlorophyte prochlorothrix hollandica; this complex was similar in chemical composition and structure to that found in cyanobacteria. peptide patterns of partial acid hydrolysates of the isolated pept ... | 1989 | 2914854 |
| supramolecular structure of the thylakoid membrane of prochlorothrix hollandica: a chlorophyll b-containing prokaryote. | prochlorothrix hollandica is a newly described photosynthetic prokaryote, which contains chlorophylls a and b. in this paper we report the results of freeze fracture and freeze etch studies of the organization of the photosynthetic thylakoid membranes of prochlorothrix. these membranes exhibit four distinct fracture faces in freeze fractured preparations, two of which are derived from membrane splitting in stacked regions of the thylakoid membrane, and two of which are derived from nonstacked re ... | 1988 | 3255758 |
| chlorophyll-protein composition of the thylakoid membrane from prochlorothrix hollandica, a prokaryote containing chlorophyll b. | the chlorophyll-protein complexes of the thylakoid membrane from prochlorothrix hollandica were identified following electrophoresis under nondenaturing conditions. five complexes, cp1-cp5, were resolved and these green bands were analyzed by spectroscopic and immunological methods. cp1 contains the photosystem i (psi) reaction center, as this complex quenched fluorescence at room temperature, and had a 77 k fluorescence emission peak at 717 nm. cp4 contains the major chlorophyll-a-binding prote ... | 1987 | 3311745 |
| partial sequence of ribulose-1,5-bisphosphate carboxylase/oxygenase and the phylogeny of prochloron and prochlorococcus (prochlorales). | the prochlorophytes, oxygenic photosynthetic prokaryotes having no phycobiliprotein but possessing chlorophylls a and b, have been proposed to have a common ancestry with green chloroplasts, yet this is still controversal. we report here that partial sequence comparisons of the large subunit of ribulose-1,5'-bisphosphate carboxylase/oxygenase, including sequence data from two prochlorophytes, prochlorococcus and prochloron, indicate that prochlorococcus is more closely related to a photosyntheti ... | 1995 | 7643418 |
| characterization of the single psba gene of prochlorococcus marinus ccmp 1375 (prochlorophyta). | dna sequence, copy number, expression and phylogenetic relevance of the psba gene from the abundant marine prokaryote p. marinus ccmp 1375 was analyzed. the 7 amino acids near the c-terminus missing in higher plant and in prochlorothrix hollandica d1 proteins are present in the derived amino acid sequence. p. marinus contains only a single psba gene. thus, this organism lacks the ability to adapt its photosystem ii by replacement of one type of d1 by another, as several cyanobacteria do. phyloge ... | 1995 | 7766900 |
| nucleotide sequence of the pete gene encoding plastocyanin from the photosynthetic prokaryote, prochlorothrix hollandica. | we have determined the nucleotide sequence of the pete gene encoding plastocyanin from the chlorophyll a/b-containing photosynthetic prokaryote, prochlorothrix hollandica. comparison of the deduced amino acid sequence encoded by the gene with the n-terminal sequence of the purified protein revealed that plastocyanin is synthesized as a precursor bearing an n-terminal domain of 34 amino acids having some structural similarity to thylakoid lumenal transit peptides identified in other organisms. th ... | 1994 | 7803460 |
| biochemical characterization of protein composition and protein phosphorylation patterns in stacked and unstacked thylakoid membranes of the prochlorophyte prochlorothrix hollandica. | we describe a procedure to separate stacked and unstacked membranes from the prochlorophyte prochlorothrix hollandica that is based on methods used for the separation of grana and stroma thylakoids from chloroplasts. stacked membranes were isolated from triton x-100-treated whole thylakoid preparations, unstacked membranes from french press disrupted cells. membrane fractions were isolated by differential centrifugation. the stacked membranes were enriched in photosystem (ps) ii and a chlorophyl ... | 1994 | 7929163 |
| the prochlorophytes: are they more than just chlorophyll a/b-containing cyanobacteria? | the prochlorophytes are a diverse group of photosynthetic prokaryotes that fall within the cyanobacterial lineage, yet lack phycobilisomes as light harvesting structures. instead, the prochlorophytes have a light-harvesting apparatus composed of the higher plant pigments chlorophylls a and b. this review discusses the evolutionary relationships among these bacteria, with focus on the structure and function of the photosynthetic apparatus. this analysis yields a consensus from studies both on pro ... | 1993 | 8481212 |
| cloning and functional analysis of the pmma gene encoding phosphomannomutase from the photosynthetic prokaryote prochlorothrix hollandica. | the pmma gene encoding a bifunctional phosphomannomutase/phosphoglucomutase (pmm/pgm) from the photosynthetic prokaryote, prochlorothrix hollandica has been cloned and sequenced. the gene encodes a 51827 da polypeptide 48% identical to the pmm of azospirillum brasilense, 37% identical to the pgms of pathogenic neisseria sp. and 37% identical to the bifunctional algc pgm/pmm of pseudomonas aeruginosa. the pmma gene encodes an enzyme having both pgm and pmm activities as judged by both enzyme assa ... | 1996 | 8765122 |
| expression of the pete gene encoding plastocyanin in the photosynthetic prokaryote, prochlorothrix hollandica. | the expression of the pete gene encoding plastocyanin (pc) in the prokaryote prochlorothrix hollandica is dependent on the presence of copper in the medium. pc protein and pete mrna are detectable only under copper (cu) replete conditions, suggesting that control of pc accumulation can occur at the level of transcription or transcript stability. addition of cu (0.3 microm) to log-phase cu-deficient cultures yields accumulation of pc to detectable levels within 12 h; transfer of cu-replete cells ... | 1996 | 8831667 |
| bacterial triterpenoids of the hopane series from the prochlorophyte prochlorothrix hollandica and their intracellular localization. | 35-o-beta-galacturonopyranosyl-, 35-o-beta-3,5-anhydro-galacturonopyranosyl- and 35-o-alpha-altruronopyranosylbacteriohopanetetrol accompanied by their 2 beta-methyl homologues have been isolated from prochlorothrix hollandica. we report here c35 triterpenoids of the hopane series in a prochlorophyte, a group of prokaryotic oxigenic phototrophs of the cyanobacterial lineage. like many cyanobacteria, p. hollandica contains a mixture of non-methylated as well as 2 beta-methylhopanoids. after side- ... | 1996 | 8944776 |
| reconstitution and characterization of a divergent plastocyanin from the photosynthetic prokaryote, prochlorothrix hollandica, expressed in escherichia coli. | plastocyanin (pc) is a copper protein that serves as a mobile electron carrier between cytochrome f and photosystem i in the light reactions of photosynthesis. despite large variability in amino acid sequences and isoelectric points, pcs from cyanobacterial and chloroplast sources reveal considerable similarities with respect to their secondary and tertiary structures. in this paper, we have expressed in escherichia coli a pc from the prokaryote prochlorothrix hollandica, and efficiently reconst ... | 1997 | 9207210 |
| the 38 kda chlorophyll a/b protein of the prokaryote prochlorothrix hollandica is encoded by a divergent pcb gene. | the chlorophyll (chl) a/b proteins of the photosynthetic prokaryotes appear to have evolved by gene duplication and divergence of the core chl a antenna family, which also includes cp43 and cp47 and the iron-stress induced chl a-binding isia proteins. we show here that prochlorothrix hollandica has a cluster of three pcb (prochlorophyte chlorophyll b) genes which are co-transcribed. the major antenna polypeptides of 32 and 38 kda are encoded by pcba and pcbc respectively. the pcbc gene is signif ... | 1998 | 9526503 |
| sequence and functional characterization of rnase p rna from the chl alb containing cyanobacterium prochlorothrix hollandica. | only a few complete sequences and very limited functional data are available for the catalytic rna component of cyanobacterial rnase p. the rnase p rna from the chl alb containing cyanobacterium prochlorothrix hollandica belongs to a rarely found structural subtype with an extended p15/16 domain. we have established conditions for optimal in vitro ribozyme activity, and determined the kinetic parameters for cleavage of pre-trna(tyr). analysis of pre-trna mutants revealed that the t-stem sequence ... | 1998 | 9654127 |
| prochlorothrix hollandica pcc 9006: genomic properties of an axenic representative of the chlorophyll a/b-containing oxyphotobacteria. | prochlorothrix hollandica is an oxygenic photosynthetic prokaryote that differs from the cyanobacteria in having chlorophyll a/b-protein complexes instead of phycobilisomes as major light-harvesting antennae. we report the isolation and culturing of an axenic strain of p. hollandica, available from the pasteur culture collection of cyanobacteria as strain pcc 9006. the strain has a mean dna base composition of 51.6 +/- 0.1 mol% g+c and a genomic complexity of 3.37 +/- 0.17 x 10(9) daltons (5,505 ... | 1997 | 9765813 |
| transcript analysis of the pcbabc genes encoding the antenna apoproteins in the photosynthetic prokaryote, prochlorothrix hollandica. | the tightly linked pcbabc genes encode the chlorophyll a/b-binding apoproteins in the oxygenic photosynthetic prokaryote prochlorothrix hollandica. northern blotting experiments employing gene-specific dna probes have identified a complex pattern of transcription from the pcb region. a large 4.4-kb transcript detected in cultures maintained in high light, low light and in darkness results from the cotranscription of all three genes, whereas pcbab, pcbbc and individual pcba, b, and c mrnas are si ... | 1998 | 9835028 |
| nmr solution structure of plastocyanin from the photosynthetic prokaryote, prochlorothrix hollandica. | the solution structure of a divergent plastocyanin (pc) from the photosynthetic prokaryote prochlorothrix hollandica was determined by homonuclear 1h nmr spectroscopy. nineteen structures were calculated from 1222 distance restraints, yielding a family of structures having an average rmsd of 0.42 +/- 0.08 a for backbone atoms and 0.71 +/- 0.07 a for heavy atoms to the mean structure. no distance constraint was violated by more than 0.26 a in the structure family. despite the low number of conser ... | 1999 | 10213601 |
| chlorophyll b and phycobilins in the common ancestor of cyanobacteria and chloroplasts. | photosynthetic organisms have a variety of accessory pigments, on which their classification has been based. despite this variation, it is generally accepted that all chloroplasts are derived from a single cyanobacterial ancestor. how the pigment diversity has arisen is the key to revealing their evolutionary history. prochlorophytes are prokaryotes which perform oxygenic photosynthesis using chlorophyll b, like land plants and green algae (chlorophyta), and were proposed to be the ancestors of ... | 1999 | 10408441 |
| the unique proline of the prochlorothrix hollandica plastocyanin hydrophobic patch impairs electron transfer to photosystem i. | a number of surface residues of plastocyanin from prochlorothrix hollandica have been modified by site-directed mutagenesis. changes have been made in amino acids located in the amino-terminal hydrophobic patch of the copper protein, which presents a variant structure as compared with other plastocyanins. the single mutants y12g, y12f, y12w, p14l, and double mutant y12g/p14l have been produced. their reactivity toward photosystem i has been analyzed by laser flash absorption spectroscopy. plots ... | 2001 | 11457853 |
| oxyphotobacteria. antenna ring around photosystem i. | the oceanic picoplankton prochlorococcus - probably the most abundant photosynthetic organism on our planet - can grow at great depths where light intensity is very low. we have found that the chlorophyll-binding proteins in a deep-living strain of this oxyphotobacterium form a ring around a trimer of the photosystem i (ps i) photosynthetic reaction centre, a clever arrangement that maximizes the capture of light energy in such dim conditions. | 2001 | 11595938 |
| computational simulation of the docking of prochlorothrix hollandica plastocyanin to potosystem i: modeling the electron transfer complex. | we have used several docking algorithms (gramm, ftdock, dot, autodock) to examine protein-protein interactions between plastocyanin (pc)/photosystem i (psi) in the electron transfer reaction. because of the large size and complexity of this system, it is faster and easier to use computer simulations than conduct x-ray crystallography or nuclear magnetic resonance experiments. the main criterion for complex selection was the distance between the copper ion of pc and the p700 chlorophyll special p ... | 2002 | 12023253 |
| light-dependent tyrosine phosphorylation in the cyanobacterium prochlorothrix hollandica. | a light-dependent tyrosine kinase activity is present in soluble extracts from the cyanobacterium prochlorothrix hollandica. the substrate of this tyrosine kinase activity is a soluble 88-kd protein that is phosphorylated when cultures of p. hollandica are adapted to high-light conditions. this phosphoprotein was identified by probing western blots of 32p-labeled soluble proteins from p. hollandica with an antibody specific for phosphotyrosine. this specificity was confirmed by competition exper ... | 1994 | 12232230 |
| plastocyanin-cytochrome f interactions: the influence of hydrophobic patch mutations studied by nmr spectroscopy. | transient complex formation between plastocyanin from prochlorothrix hollandica and cytochrome f from phormidium laminosum was investigated using nuclear magnetic resonance (nmr) spectroscopy. binding curves derived from nmr titrations at 10 mm ionic strength reveal a 1:1 stoichiometry and a binding constant of 6 (+/-2) x 10(3) m(-1) for complex formation, 1 order of magnitude larger than that for the physiological plastocyanin-cytochrome f complex from ph. laminosum. chemical-shift perturbation ... | 2002 | 12501198 |
| mutagenesis of prochlorothrix plastocyanin reveals additional features in photosystem i interactions. | three surface residues of plastocyanin from prochlorothrix hollandica have been modified by site-directed mutagenesis. changes have been made in methionine 33, located in the hydrophobic patch of the copper protein, and in arginine 86 and proline 53, both located in the eastern hydrophilic area. the reactivity toward photosystem i of single mutants m33n, p53a, p53e, r86q, r86e, and the double mutant m33n/p14l has been studied by laser flash absorption spectroscopy. all the mutations yield increa ... | 2003 | 12509429 |
| detection of prochlorothrix in brackish waters by specific amplification of pcb genes. | prochlorothrix hollandica is the only filamentous chlorophyll b (chlb)-containing oxyphotobacterium that has been found in freshwater habitats to date. chlb serves as a light-harvesting pigment which is bound to special binding proteins (pcb). even though prochlorothrix was initially characterized as a highly salt-sensitive species, we detected it in a brackish water environment that is characterized by salinities of up to 12 practical salinity units. using pcr and reverse transcription, we ampl ... | 2003 | 14532086 |
| characteristic fragmentation of bacteriohopanepolyols during atmospheric pressure chemical ionisation liquid chromatography/ion trap mass spectrometry. | bacteriohopanepolyols (bhps) fragment via characteristic pathways during atmospheric pressure chemical ionisation liquid chromatography/ion trap mass spectrometry (apci-lc/ms(n)). comparison of the ms(2) spectra of bacteriohopane-32,33,34,35-tetrol (bht) and 2 beta-methylbacteriohopane-32,33,34,35-tetrol has confirmed the previously proposed ring-c cleavage occurring between c-9 and 11 and c-8 and 14. this fragmentation, diagnostic of all hopanoids, also occurs in bhps containing an amino group ... | 2003 | 14673828 |
| domain structures of chlorophyllide a oxygenase of green plants and prochlorothrix hollandica in relation to catalytic functions. | chlorophyll b is a photosynthetic antenna pigment found in prochlorophytes and chlorophytes. in chlorophytes, its biosynthesis regulates the photosynthetic antenna size. chlorophyll b is synthesized from chlorophyll a in a two-step oxygenation reaction by chlorophyllide a oxygenase (cao). in this study, we first identified the entire sequence of a prochlorophyte cao gene from prochlorothrix hollandica to compare it with those from chlorophytes, and we examined the catalytic activity of the gene ... | 2004 | 14716565 |
| molecular characterization of cyanobacterial diversity in a shallow eutrophic lake. | we have studied the diversity of pelagic cyanobacteria in lake loosdrecht, the netherlands, through recovery and analysis of small subunit ribosomal rna gene sequences from lake samples and cyanobacterial isolates. we used an adapted protocol for specific amplification of cyanobacterial rdna for denaturing gradient gel electrophoresis (dgge) analysis. this protocol enabled direct comparison of cyanobacterial community profiles with overall bacterial profiles. the theoretical amplification specif ... | 2005 | 15683397 |
| antenna ring around trimeric photosystem i in chlorophyll b containing cyanobacterium prochlorothrix hollandica. | prochlorothrix hollandica is one of the three known species of an unusual clade of cyanobacteria (formerly called "prochlorophytes") that contain chlorophyll a and b molecules bound to intrinsic light-harvesting antenna proteins. here, we report the structural characterization of supramolecular complex consisting of photosystem i (psi) associated with the chlorophyll a/b-binding pcb proteins. electron microscopy and single particle image analysis of negatively stained preparations revealed that ... | 2005 | 15949978 |
| a brownian dynamics study of the interaction of phormidium cytochrome f with various cyanobacterial plastocyanins. | brownian dynamics simulations were used to study the role of electrostatic forces in the interactions of cytochrome f from the cyanobacterium phormidium laminosum with various cyanobacterial plastocyanins. both the net charge on the plastocyanin molecule and the charge configuration around h92 (h87 in higher plants) are important in determining the interactions. those plastocyanins (pcs) with a net charge more negative than -2.0, including those from synechococcus sp. pcc7942, synechocystis sp. ... | 2006 | 16214856 |
| prochlorophyta - a matter of class distinctions. | prochloron (a marine symbiont) and prochlorothrix (from freshwater plankton) contain chlorophylls a and b; prochlorococcus (common in marine picoplankton) contains divinyl-chlorophylls a and b. like cyanophytes they are all clearly photosynthetic prokaryotes, but since they contain no blue or red bilin pigment they were assigned to a new algal sub-class, the prochlorophyta. however, since their possible phylogenetic relationships to ancestral green-plant chloroplasts have not received support fr ... | 2002 | 16245104 |
| photosynthesis of prochlorothrix hollandica under sulfide-rich anoxic conditions. | the photosynthetic activity and photosystem ii fluorescence of prochlorothrix hollandica were studied under anoxic, sulfide-rich conditions. oxygenic photosynthetic activity with water as the electron donor was highly resistant to inhibition by sulfide. cells still retained 50% of their oxygenic photosynthetic activity at >1 mm sulfide. in the presence of dcmu [n-(3,4-dichlorophenyl)-n(prm1)-dimethylurea], an inhibitor of photosystem ii activity, p. hollandica cells exhibited a low but significa ... | 1997 | 16535689 |
| pigment shuffling in antenna systems achieved by expressing prokaryotic chlorophyllide a oxygenase in arabidopsis. | the organization of pigment molecules in photosystems is strictly determined. the peripheral antennae have both chlorophyll a and b, but the core antennae consist of only chlorophyll a in green plants. furthermore, according to the recent model obtained from the crystal structure of light-harvesting chlorophyll a/b-protein complexes ii (lhcii), individual chlorophyll-binding sites are occupied by either chlorophyll a or chlorophyll b. in this study, we succeeded in altering these pigment organiz ... | 2006 | 16574646 |
| functional analysis of the photosynthetic apparatus of prochlorothrix hollandica (prochlorales), a chlorophyll b containing procaryote. | light-shade adaptation of the chlorophyll a/b containing procaryote prochlorothrix hollandica was studied in semicontinuous cultures adapted to 8, 80 and 200 mumole quanta per square meter per second. chlorophyll a contents based on dry weight differed by a factor of 6 and chlorophyll b by a factor of 2.5 between the two extreme light conditions. light utilization efficiencies determined from photosynthesis response curves were found to decrease in low light grown cultures due to lower light har ... | 1989 | 16667098 |
| identification of chlorophyllide a oxygenase in the prochlorococcus genome by a comparative genomic approach. | chl b is a major photosynthetic pigment of peripheral antenna complexes in chlorophytes and prochlorophytes. chl b is synthesized by chlorophyllide a oxygenase (cao), an enzyme that has been identified from higher plants, moss, green algae and two groups of prochlorophytes, prochlorothrix and prochloron. based on these results, we previously proposed the hypothesis that all of the chl b synthesis genes have a common origin. however, the cao gene is not found in whole genome sequences of prochlor ... | 2006 | 17071624 |
| association of chlorophyll a/b-binding pcb proteins with photosystems i and ii in prochlorothrix hollandica. | action spectra for photosystem ii (psii)-driven oxygen evolution and of photosystem i (psi)-mediated h(2) photoproduction and photoinhibition of respiration were used to determine the participation of chlorophyll (chl) a/b-binding pcb proteins in the functions of pigment apparatus of prochlorothrix hollandica. comparison of the in situ action spectra with absorption spectra of psii and psi complexes isolated from the cyanobacterium synechocystis 6803 revealed a shoulder at 650 nm that indicated ... | 2007 | 17174934 |
| salinity tolerance of the chlorophyll b-synthesizing cyanobacterium prochlorothrix hollandica strain sag 10.89. | ecophysiological investigations on the salinity acclimation of the cyanobacterium prochlorothrix hollandica sag 10.89 led to significantly revised salinity tolerance limits. besides potential effects of cultivation techniques, clear ion composition effects mainly explain formerly described hypersensitivity to nacl-mediated salinity and lack of osmolyte detection. an extraordinarily broad plasticity of cellular chlorophyll a/b ratios occurred with variations of nacl-induced salinity. photosynthes ... | 2008 | 17874260 |
| dynamics in the transient complex of plastocyanin-cytochrome f from prochlorothrix hollandica. | the nature of transient protein complexes can range from a highly dynamic ensemble of orientations to a single well-defined state. this represents variation in the equilibrium between the encounter and final, functional state. the transient complex between plastocyanin (pc) and cytochrome f (cytf) of the cyanobacterium prochlorothrix hollandica was characterized by nmr spectroscopy. intermolecular pseudocontact shifts and chemical shift perturbations were used as restraints in docking calculatio ... | 2008 | 18201089 |
| fitting light saturation curves measured using modulated fluorometry. | a blue diode pam (pulse amplitude modulation) fluorometer was used to measure rapid photosynthesis (p) versus irradiance (e) curves (p vs. e curves) in synechococcus (classical cyanobacteria), prochlorothrix (prochlorophyta), chlorella (chlorophyta), rhodomonas (cryptophyta), phaeodactylum (bacillariophyta) acaryochloris (chl d/a cyanobacteria) and subterranean clover (trifolium subterraneum, papilionaceae, angiospermae). effective quantum yield (phi(psii)) versus irradiance curves could be desc ... | 2008 | 18415696 |
| detecting the phosphate status of phytoplankton by enzyme-labelled fluorescence and flow cytometry. | the novel phosphatase substrate, elf-97 phosphate, yields intensely green fluorescent precipitates of elf-97 alcohol (elfa) upon enzymatic dephosphorylation, and thereby traces phosphatase activity back to its producer. in this study, we show that elfa fluorescence is a useful tool in flow cytometric analysis of natural phytoplankton populations. presence of endogenous fluorescent pigments allowed flow cytometric distinction of clusters in the phytoplankton community in lake loosdrecht (the neth ... | 2004 | 19712428 |
| localization of pcb antenna complexes in the photosynthetic prokaryote prochlorothrix hollandica. | the freshwater filamentous green oxyphotobacterium prochlorothrix hollandica is an unusual oxygenic photoautotrophic cyanobacterium differing from most of the others by the presence of light-harvesting pcb antenna binding both chlorophylls a and b and by the absence of phycobilins. the pigment-protein complexes of p. hollandica sag 10.89 (ccap 1490/1) were isolated from dodecylmaltoside solubilized thylakoid membranes on sucrose density gradient and characterized by biochemical, spectroscopic an ... | 2010 | 19761753 |
| carotenoids in energy transfer and quenching processes in pcb and pcb-ps i complexes from prochlorothrix hollandica. | chlorophyll (chl) a/b-binding proteins from prochlorothrix hollandica known as pcb antennae were studied by femtosecond transient absorption technique to identify energy transfer rates and pathways in pcb and pcb-ps i complexes. carotenoids transfer energy to chl with low efficiency of approximately 25% in pcb complexes. interestingly, analysis of transient absorption spectra identified a pathway from the hot s(1) state of zeaxanthin and/or beta-carotene as the major energy transfer channel betw ... | 2010 | 20583762 |