25 Result(s)
within
English
Life Sciences
Biochemistry, general
Klaas J. Hellingwerf
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Protocol
Development of a Light-Dependent Protein Histidine Kinase
Phosphorylation plays a critical role in facilitating signal transduction in prokaryotic and eukaryotic organisms. Our study introduces a tool for investigation of signal diffusion in a biochemical regulation ...
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Article
Open AccessExploring the low photosynthetic efficiency of cyanobacteria in blue light using a mutant lacking phycobilisomes
The ubiquitous chlorophyll a (Chl a) pigment absorbs both blue and red light. Yet, in contrast to green algae and higher plants, most cyanobacteria have much lower photosynthetic rates in blue than in red light. ...
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Article
Open AccessBlue light reduces photosynthetic efficiency of cyanobacteria through an imbalance between photosystems I and II
Several studies have described that cyanobacteria use blue light less efficiently for photosynthesis than most eukaryotic phototrophs, but comprehensive studies of this phenomenon are lacking. Here, we study t...
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Article
Open AccessSpectrally decomposed dark-to-light transitions in Synechocystis sp. PCC 6803
Photosynthetic activity and respiration share the thylakoid membrane in cyanobacteria. We present a series of spectrally resolved fluorescence experiments where whole cells of the cyanobacterium Synechocystis sp....
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Chapter
Photoreceptor Proteins from Purple Bacteria
Purple bacteria contain representatives of four of the six main families of photoreceptor proteins: phytochromes, BLUF domain containing proteins, xanthopsins (i.e., photoactive yellow proteins), and phototrop...
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Protocol
Prokaryotic Phototaxis
Microorganisms have various mechanisms at their disposal to react to (changes in) their ambient light climate (i.e., intensity, color, direction, and degree of polarization). Of these, one of the best studied ...
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Chapter
Light-induced behavioral responses (‘phototaxis’) in prokaryotes
Light-induced sensory responses are among the oldest scientific observations on bacterial behavior. Various types of response have been characterized physiologically in detail. However, the molecular basis of ...
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Article
Light-induced behavioral responses (`phototaxis') in prokaryotes
Light-induced sensory responses are among the oldest scientific observations on bacterial behavior. Various types of response have been characterized physiologically in detail. However, the molecular basis of ...
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Article
Phototransformation of green fluorescent protein with UV and visible light leads to decarboxylation of glutamate 222
Wild type green fluorescent protein (GFP) from Aequorea victoria absorbs predominantly at 398 nm. Illumination with UV (254 nm) or visible (390 nm) light transforms this state (GFP398) into one absorbing at 483 n...
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Article
Alkalispirillum mobile gen. nov., spec. nov., an alkaliphilic non-phototrophic member of the Ectothiorhodospiraceae
From cultures of the anoxygenic phototroph Halorhodospira halophila SL-1, an aerobic, gram-negative spirillum was isolated. This moderately halophilic, alkaliphilic bacterium was motile by means of a single pola...
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Chapter
Sensing of Green Light in Complementary Chromatic Adaptation of the Cyanobacterium Calothrix sp.
Light harvesting is essential for phototrophic organisms. The reaction centers of PS2 and PS1 in cyanobacteria contain chl a, † a ubiquitous pigment that absorbs light in two spectral domains. In the blue, absorp...
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Article
Characterization and transcriptional regulation of the Synechocystis PCC 6803, petH gene, encoding ferredoxin-NADP+ oxidoreductase: involvement of a novel type of divergent operator
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Article
Structural and dynamic changes of photoactive yellow protein during its photocycle in solution
Light irradiation of photoactive yellow protein (PYP) induces a photocycle, in which red-shifted (pR) and blue-shifted (pB) intermediates have been characterized. An NMR study of the long-lived pB intermediate...
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Article
Characterization and transcriptional regulation of the Synechocystis PCC 6803 petH gene, encoding ferredoxin-NADP+ oxidoreductase: involvement of a novel type of divergent operator
The petH gene, encoding ferredoxin-NADP+ oxidoreductase (FNR), has been characterised in the unicellular cyanobacterium Synechocystis PCC 6803. Its product, FNR, was heterologously produced and functionally chara...
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Article
Effect of nitrogen sources on the regulation of extracellular lipase production in Acinetobacter calcoaceticus strains
Extracellular lipase production and lipA expression were studied in A.calcoaceticus strains in relation to the nitrogen sources. Addition of casamino-acids or tryptone improved 2–3 times lipase yield as compared ...
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Article
Physiological regulation of competence induction for natural transformation in Acinetobacter calcoaceticus
Acinetobacter calcoaceticus induced competence for natural transformation maximally after dilution of a stationary culture into fresh medium. Competence was gradually lost during prolonged exponential growth and...
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Chapter
Comparison of Retinal-Based and Chlorophyll-Based Photosynthesis: A Biothermokinetic Description of Photochemical Reaction Centers
Life on earth depends on the transformation of sunlight (electromagnetic radiation) into biologically useful chemical energy. The first step in this process is the conversion of the free energy from sunlight i...
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Article
A Kdp-like, high-affinity, K+-translocating ATPase is expressed during growth of Rhodobacter sphaeroides in low potassium media
Cells of the purple non-sulphur bacterium Rhodobacter sphaeroides express a high-affinity K+ uptake system when grown in media with low K+ concentrations. Antibodies againts the catalytic KdpB protein or the whol...
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Chapter
Carotenoid Absorbance Changes in Liposomes Reconstituted with Pigment-Protein Complexes from Rhodobacter Sphaeroides
The electrochromic behaviour of carotenoids has been widely used to determine the electrical potential difference (∆ψ) across photosynthetic membranes, like chromatophores [1] and bacterial cells [2,3]. The ca...
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Chapter and Conference Paper
Functional Reconstitution of Photosynthetic Reaction Centre Complexes from Rhodopseudomonas Palustris
Reconstitution is a powerful technique in the elucidation of the mechanisms involved in membrane associated biological energy transduction (see for example Racker & Stoeckenius, 1974). For proton motive force ...
