Assessment of Rhodopseudomonas sphaeroides chromatophore membrane asymmetry through bilateral antiserum adsorption studies

Collins, Mary Lynne Perille; Mallon, David E.; Niederman, Robert A.

doi:10.1128/jb.143.1.221-230.1980

Cited by 23 publications

(7 citation statements)

References 33 publications

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“…about 20% of the reduced pyridoxine 5'-phosphate conjugates at the periplasmic aspect of the ICM were exposed in the isolated chromatophores. This agrees with previous findings (3,12) that about 80% of such chromatophores are isolated as sealed vesicles with their cytoplasmic aspect exposed and suggests further that the majority of the periplasmic aspect of the ICM was surface labeled by this procedure.…”

Section: Resultssupporting

confidence: 93%

Intracellular localization of photosynthetic membrane growth initiation sites in Rhodopseudomonas sphaeroides

Inamine¹,

Houten²,

Niederman³

1984

J Bacteriol

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Putative membrane invagination sites at which intracytoplasmic photosynthetic membrane growth is initiated in Rhodopseudomonas sphaeroides can be isolated in an upper pigmented fraction by rate-zone sedimentation. The intracellular localization of membranes present in the isolated fraction was investigated with the impermeant surface-labeling reagent pyridoxal 5'-phosphate, which has been shown to diffuse into the periplasmic space and to label proteins of both the peripheral cytoplasmic membrane and the mature intracytoplasmic membrane. A comparison of the extent of labeling at 25 and 0°C was consistent with the possibility that membranes present in the upper pigmented fraction arise from sites near the cell periphery. Pronase digestion of the surface-labeled membranes suggested further that the purified upper fraction consisted largely of open membrane fragments and that the majority of the intracytoplasmic membrane is labeled by this procedure. The pigmented membrane growth initiation sites were separated partially from undifferentiated respiratory cytoplasmic membrane also present in the upper fraction.

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Section: Resultssupporting

confidence: 93%

Intracellular localization of photosynthetic membrane growth initiation sites in Rhodopseudomonas sphaeroides

Inamine¹,

Houten²,

Niederman³

1984

J Bacteriol

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“…5), although the evidence in this case is indirect. The membrane topology of the photosynthetic reaction center has been determined in several bacteria (16,42,183,231,240,257). In the organisms examined, one or more of the reaction center subunits (H, M, or L) are exposed at the periplasmic surface of the membrane.…”

Section: Methods Of Enzyme Localizationmentioning

confidence: 99%

In bacteria which grow on simple reductants, generation of a proton gradient involves extracytoplasmic oxidation of substrate.

Hooper¹,

DiSpirito²

1985

Microbiological Reviews

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“…Assays of ferrocytochrome c photo-oxidation in the presence and absence of octyl-,f-D-glucopyranoside suggested that these preparations consist of -900% 'inside-out' ICM vesicles with the cytoplasmic aspect of the ICM exposed [20]. Preparation of spheroplasts Spheroplasts were prepared essentially as described previously [21]. Photoheterotrophically grown cells were pelleted and washed twice with 1 mM Tris/HCl, pH 7.5, resuspended to an A680 of 6.5 in 50 mM Tris/HCI, pH 7.5, containing 25 % (w/v) sucrose, and stirred at room temperature for 10 min, followed by addition of 0.1 vol.…”

Section: Introductionmentioning

confidence: 99%

Topological organization of the Rieske iron-sulphur protein and subunit IV in the cytochrome bc1 complex of Rhodobacter sphaeroides

Niederman

1995

Biochemical Journal

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The ubiquinol-cytochrome c2 oxidoreductases (cytochrome bc1 complex) of Rhodobacter sphaeroides contains highly conserved cytochrome b, cytochrome c1 and Rieske FeS subunits, as well as a unique 14 kDa polypeptide, designated as subunit IV, thought to function as a ubiquinol-binding protein [Yu and Yu (1991) Biochemistry 30, 4934-4939]. As the topology of subunit IV is unknown and that of the FeS subunit remains a matter of debate, both the inner (cytoplasmic) and outer (periplasmic) surfaces of the intracytoplasmic membrane (ICM) were digested with proteinase K, and cleavage products were identified by immunoblotting. In uniformly oriented chromatophore vesicles (inner ICM surface exposed), fragments of approx. 4 and 1 kDa were removed from subunit IV and the FeS protein respectively. Neither subunit IV nor the FeS protein was cleaved from the outer ICM surface as exposed in osmotically protected spheroplasts or as presented to proteinase K after microencapsulation of the protease in unilamellar liposomes and fusion of these structures to chromatophore vesicles. Studies with the isolated bc1 complex, however, suggested that the C-terminal domain of the Rieske FeS, thought to reside on the periplasmic side of the ICM, was resistant to proteinase K. Overall, these results suggest a single N-terminal transmembrane helix for the FeS protein, with exposure of the N-terminus to the cytoplasm and an orientation in which a major, N-terminal portion of subunit IV is located in the cytoplasm with the predicted C-terminal transmembrane domain anchoring this polypeptide to the membrane.

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Assessment of Rhodopseudomonas sphaeroides chromatophore membrane asymmetry through bilateral antiserum adsorption studies

Abstract: The asymmetric structure of the Rhodopseudomonas sphaeroides chromatophore membrane was examined in detail by crossed immunoelectrophoresis techniques. Because these methods are quantitative and allow increased resolu

Cited by 23 publications

References 33 publications

Intracellular localization of photosynthetic membrane growth initiation sites in Rhodopseudomonas sphaeroides

Intracellular localization of photosynthetic membrane growth initiation sites in Rhodopseudomonas sphaeroides

In bacteria which grow on simple reductants, generation of a proton gradient involves extracytoplasmic oxidation of substrate.

Topological organization of the Rieske iron-sulphur protein and subunit IV in the cytochrome bc1 complex of Rhodobacter sphaeroides

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