Structure of the Purple Membrane

Blaurock, A.E.; Stoeckenius, Walther

doi:10.1038/newbio233152a0

Cited by 411 publications

(215 citation statements)

References 8 publications

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“…Freeze-fracturing techniques have been described (2,5). To obtain an estimate of the proportion of purple membrane in electron micrographs of freeze-fractured cells, the areas of purple membrane and other surface membrane ("red membrane"; ref.…”

Section: Methodsmentioning

confidence: 99%

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Functions of a New Photoreceptor Membrane

Oesterhelt

Stoeckenius

1973

Proc. Natl. Acad. Sci. U.S.A.

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1,055

564

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The purple membrane of Halobacterium halobium contains only one protein, bacteriorhodopsin, which closely resembles the visual pigments of animals. Light The extreme halophile Halobacterium halobium synthesizes cell membrane that contains a rhodopsin-like protein, bacteriorhodopsin. It forms distinct patches with a hexagonal lattice structure in the plane of the membrane. The patches have been isolated and show a strong absorption band near 560 nm. They have been termed the purple membrane (1, 2).Photoreactions similar to those in rhodopsin have been observed in bacteriorhodopsin. Illumination causes a transient decrease in the absorption maximum near 560 nm with a corresponding increase in absorption near 415 nm. This finding suggests the possibility that the purple membrane functions as a photoreceptor. We, therefore, investigated light responses in halobacteria and found: phototaxis; ATP synthesis; and changes in 02 consumption, purple membrane biosynthesis, and proton translocation. We report here on the last three effects, which suggest that the purple membrane may function as an energy-coupling membrane for light.

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Section: Methodsmentioning

confidence: 99%

“…The patches have been isolated and show a strong absorption band near 560 nm. They have been termed the purple membrane (1,2).…”

mentioning

confidence: 99%

Functions of a New Photoreceptor Membrane

Oesterhelt

Stoeckenius

1973

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

1,055

564

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“…Under the native condition, bR forms trimers that assemble into a two-dimensional hexagonal lattice called the purple membrane (PM) (Blaurock, 1971). Previously, numerous structural studies of bR in PM were performed under unphotolyzed (Sass et al, 2000) or frozen activated (Luecke et al, 1999;Subramaniam and Henderson, 2000;Vonck, 2000, Lanyi andSchobert, 2003;Hirai and Subramaniam, 2009) states.…”

Section: Introductionmentioning

confidence: 99%

Role of trimer–trimer interaction of bacteriorhodopsin studied by optical spectroscopy and high-speed atomic force microscopy

Yamashita

Inoue

Shibata

et al. 2013

Journal of Structural Biology

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Bacteriorhodopsin (bR) trimers form a two-dimensional hexagonal lattice in the purple membrane of Halobacterium salinarum. However, the physiological significance of forming the lattice has long been elusive. Here, we study this issue by comparing properties of assembled and non-assembled bR trimers using directed mutagenesis, high-speed atomic force microscopy (HS-AFM), optical spectroscopy, and a proton pumping assay. First, we show that the bonds formed between W12 and F135 amino acid residues are responsible for trimer-trimer association that leads to lattice assembly; the lattice is completely disrupted in both W12I and F135I mutants. HS-AFM imaging reveals that both crystallized D96N and non-crystallized D96N/W12I mutants undergo a large conformational change (i.e., outward E-F loop displacement) upon light-activation. However, lattice disruption significantly reduces the rate of conformational change under continuous light illumination. Nevertheless, the quantum yield of M-state formation, measured by low-temperature UV-visible spectroscopy, and proton pumping efficiency are unaffected by lattice disruption. From these results, we conclude that trimer-trimer association plays essential roles in providing bound retinal with an appropriate environment to maintain its full photo-reactivity and in maintaining the natural photo-reaction pathway.

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“…In particular, it has been shown that proteins in native membranes may not diffuse freely but are in fact confined to specific domains. Cells use several confining mechanisms such as anchoring to the cytoskeleton through hetero-bifunctional proteins (Byers and Branton, 1985), diffusion barriers formed by the accumulation of proteins anchored to cytoskeleton meshes (Halenda et al, 1987;Nakada et al, 2003), or self-assembly into large two-dimensional (2D) crystalline patches, as in the case of bacteriorhodopsin (bR), a light-driven proton pump found in the so-called purple membranes (PM) of Halobacterium salinarum (Blaurock, 1971). Despite these advances, an understanding of the membrane dynamics at the nanoscale remains a major challenge due primarily to the lack of measurement techniques allowing simultaneous spatial and temporal observation of single molecules within native membranes.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of bacteriorhodopsin 2D crystal observed by high-speed atomic force microscopy

Yamashita

Voïtchovsky

Uchihashi

et al. 2009

Journal of Structural Biology

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We have used high-speed atomic force microscopy to study the dynamics of bacteriorhodopsin (bR) molecules at the free interface of the crystalline phase that occurs naturally in purple membrane.Our results reveal temporal fluctuations at the crystal edges arising from the association and dissociation of bR molecules, most predominantly pre-formed trimers. Analysis of the dissociation kinetics yields an estimate of the inter-trimer single-bond energy of -0.9 kcal/mol. Rotational motion of individual bound trimers indicates that the inter-trimer bond involves W10-W12 tryptophan residues.

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Structure of the Purple Membrane

Cited by 411 publications

References 8 publications

Functions of a New Photoreceptor Membrane

Functions of a New Photoreceptor Membrane

Role of trimer–trimer interaction of bacteriorhodopsin studied by optical spectroscopy and high-speed atomic force microscopy

Dynamics of bacteriorhodopsin 2D crystal observed by high-speed atomic force microscopy

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