Exemplar Abstract for Ectothiorhodospira halochloris Imhoff and Trüper 1979 (Approved Lists 1980) and Halorhodospira halochloris (Imhoff and Trüper 1979) Imhoff and Süling 1997.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Sarah Wigley ◽  
George M Garrity
Keyword(s):  
Ectothiorhodospira Halochloris

Structural analysis of the photosynthetic membrane from Ectothiorhodospira halochloris

1983 ◽  
Vol 41 ◽  
pp. 740-741
Author(s):  
H. Engelhardt ◽  
R. Guckenberger ◽  
W. Baumeister
Keyword(s):  
Lattice Structure ◽  
Bacterial Species ◽  
Hexagonal Lattice ◽  
Reaction Centre ◽  
Photosynthetic Membrane ◽  
Rhodopseudomonas Viridis ◽  
Photosynthetic Membranes ◽  
Ectothiorhodospira Halochloris ◽  
Main Components

Bacterial photosynthetic membranes contain, apart from lipids and electron transport components, reaction centre (RC) and light harvesting (LH) polypeptides as the main components. The RC-LH complexes in Rhodopseudomonas viridis membranes are known since quite seme time to form a hexagonal lattice structure in vivo; hence this membrane attracted the particular attention of electron microscopists. Contrary to previous claims in the literature we found, however, that 2-D periodically organized photosynthetic membranes are not a unique feature of Rhodopseudomonas viridis. At least five bacterial species, all bacteriophyll b - containing, possess membranes with the RC-LH complexes regularly arrayed. All these membranes appear to have a similar lattice structure and fine-morphology. The lattice spacings of the Ectothiorhodospira haloohloris, Ectothiorhodospira abdelmalekii and Rhodopseudomonas viridis membranes are close to 13 nm, those of Thiocapsa pfennigii and Rhodopseudomonas sulfoviridis are slightly smaller (∼12.5 nm).

The Photosynthetic Apparatus of Ectothiorhodospira halochloris 3. Effect of Proteolytic Digestion on the Photoactivity

1986 ◽  
Vol 41 (9-10) ◽  
pp. 873-880 ◽  
Author(s):  
R. Steiner ◽  
B. Kalumenos ◽  
H. Scheer
Keyword(s):  
Molecular Weight ◽  
Reaction Center ◽  
Photosynthetic Apparatus ◽  
Photochemical Activity ◽  
Proteinase K ◽  
Proteolytic Digestion ◽  
Polypeptide Composition ◽  
Difference Spectra ◽  
Ectothiorhodospira Halochloris ◽  
The One

Abstract Photsynthetic membranes of Rhodopseudomonas virids and Ectothiorhodospira halochloris were treated with proteinase K. The photochemical activity (light minus dark difference spectra) were compared to the polypeptide composition (SDS-polyacrylamide gel analysis). In E. halo­chloris, difference bands appear at 806 (+), 838 (+) and 854 nm (-) . All three decrease in intensity upon incubation with proteinase K., but this decrease is much slower than the proteolysis of both the reaction center and antenna related polypeptides. Photochemical activity remains high as long as a small part of the RC and two lower molecular weight polypeptides M* (22.0 kDa) and B* (15.3 kDa) are present. The M subunit is the most stable polypeptide in the RC of Rp. viridis too, and the photochemical activity is related to the remainder of this and to the one newly formed polypeptide (15.3 kDa), but doesn’t show the typical absorption shift of the antenna (B 800/1020 → B 800/960). The results are discussed quantitatively and compared to those obtained from Bchl α containing organisms.

⊿2,10-Phytadienol as Esterifying Alcohol of Bacteriochlorophyll b from Ectothiorhodospira halochloris

1981 ◽  
Vol 36 (5-6) ◽  
pp. 417-420 ◽  
Author(s):  
R. Steiner ◽  
W. Schäfer ◽  
I. Bios ◽  
H. Wieschhoff ◽  
H. Scheer
Keyword(s):  
Mass Spectroscopy ◽  
Hplc Analysis ◽  
Photosynthetic Bacterium ◽  
Vis Spectroscopy ◽  
Ectothiorhodospira Halochloris ◽  
Bacteriochlorophyll B ◽  
The One

Abstract Bacteriochlorophyll b (bchl b) has been isolated from the halophilic photosynthetic bacterium, Ectothiorhodospira halochloris. The pigment and a series of derivatives thereof are different from Bchl b from Rhodopseudomonas viriais by HPLC analysis, but similar by uv-vis spectroscopy. The chromatographic difference originates in different esterifying alcohols in the two pigments. The one from Rp. viridis (Bchl bp) is esterified with ⊿2-phytaenol (phytol), that from E. halochloris (Bchl b⊿2,10) with ⊿2,10-phytadienol. The structure of the latter has been established by isolation of the alcohol from the purified pigment, followed by (i) gaschromatography-mass spectroscopy and (ii) ozonolysis and dinitrophenylhydrazon-formation of the cleavage products, which were identified by gaschromatography-mass spectroscopy as 6-methyl-heptan-2-one, and 4-methyl-nona-1,8-dione.

The Photosynthetic Apparatus of Ectothiorhodospira halochloris 2. Accessibility of the Membrane Polypeptides to Partial Proteolysis and Antenna Polypeptide Assignments to Specific Chromophores

1986 ◽  
Vol 41 (5-6) ◽  
pp. 571-578 ◽  
Author(s):  
R. Steiner ◽  
A. Angerhofer ◽  
H. Scheer
Keyword(s):  
Absorption Band ◽  
Photosynthetic Bacteria ◽  
Photosynthetic Apparatus ◽  
Reaction Centers ◽  
Proteinase K ◽  
Spectral Changes ◽  
Membrane Surfaces ◽  
Sds Page ◽  
Ectothiorhodospira Halochloris ◽  
Cytoplasmic Side

E. halochloris thylakoids and spheroplasts were treated with trypsin, thermolysin or proteinase K to determine which proteins are exposed at the different membrane surfaces. Based on SDS polyacrylamide analysis, all 9 polypeptides are exposed on the cytoplasmic side. Only one (28 kDa) is accessible from the periplasmic side. This polypeptide is generally isolated as the H-subunit of the reaction centers of photosynthetic bacteria, but is in the case of E. halochloris rather isolated with the antenna (B 800/1020) (Steiner and Scheer, Biochim . Biophys. Acta 807, 278, 1983).Proteolysis is accompanied by a shift of the absorption band at longest wavelengths from 1020 to 960 nm (B 800/960), which upon standing is shifted further to 680 nm (“B” 800/680). The spectral changes are similar to the ones reported earlier for treatment with acid, and are also inducible with urea. The correlation of SDS-PAGE and absorption spectroscopy shows, that the chroophores absorbing at 1020 nm are transformed sim ultaneously with the degradation of the 6.5 kDa (=α) polypeptide.

Sign in / Sign up

Export Citation Format

Share Document