bacteriorhodopsin

Summary

Gene Symbol: bacteriorhodopsin
Description: rhodopsin
Alias: VNG1467G
Species: Halobacterium sp. NRC-1

Top Publications

  1. Luecke H, Schobert B, Richter H, Cartailler J, Lanyi J. Structure of bacteriorhodopsin at 1.55 A resolution. J Mol Biol. 1999;291:899-911 pubmed publisher
    Th?e atomic structure of the light-driven ion pump bacteriorhodopsin and the surrounding lipid matrix was determined by X-ray diffraction of crystals grown in cubic lipid phase...
  2. Belrhali H, Nollert P, Royant A, Menzel C, Rosenbusch J, Landau E, et al. Protein, lipid and water organization in bacteriorhodopsin crystals: a molecular view of the purple membrane at 1.9 A resolution. Structure. 1999;7:909-17 pubmed
    b>Bacteriorhodopsin (bR) from Halobacterium salinarum is a proton pump that converts the energy of light into a proton gradient that drives ATP synthesis...
  3. Subramaniam S, Henderson R. Molecular mechanism of vectorial proton translocation by bacteriorhodopsin. Nature. 2000;406:653-7 pubmed publisher
    b>Bacteriorhodopsin, a membrane protein with a relative molecular mass of 27,000, is a light driven pump which transports protons across the cell membrane of the halophilic organism Halobacterium salinarum...
  4. Facciotti M, Rouhani S, Burkard F, Betancourt F, Downing K, Rose R, et al. Structure of an early intermediate in the M-state phase of the bacteriorhodopsin photocycle. Biophys J. 2001;81:3442-55 pubmed publisher
    The structure of an early M-intermediate of the wild-type bacteriorhodopsin photocycle formed by actinic illumination at 230 K has been determined by x-ray crystallography to a resolution of 2.0 A...
  5. Faham S, Bowie J. Bicelle crystallization: a new method for crystallizing membrane proteins yields a monomeric bacteriorhodopsin structure. J Mol Biol. 2002;316:1-6 pubmed publisher
    ..The method is flexible and simple to use. As a test case, bacteriorhodopsin (bR) from Halobacterium salinarum was crystallized from a bicellar solution, yielding a new bR crystal form...
  6. Khorana H, Gerber G, Herlihy W, Gray C, Anderegg R, Nihei K, et al. Amino acid sequence of bacteriorhodopsin. Proc Natl Acad Sci U S A. 1979;76:5046-50 pubmed
    The complete primary structure of the purple membrane protein bacteriorhodopsin, which contains 248 amino acid residues, has been determined...
  7. Nishikawa T, Murakami M, Kouyama T. Crystal structure of the 13-cis isomer of bacteriorhodopsin in the dark-adapted state. J Mol Biol. 2005;352:319-28 pubmed
    The atomic structure of the trans isomer of bacteriorhodopsin was determined previously by using a 3D crystal belonging to the space group P622...
  8. Schertler G, Bartunik H, Michel H, Oesterhelt D. Orthorhombic crystal form of bacteriorhodopsin nucleated on benzamidine diffracting to 3.6 A resolution. J Mol Biol. 1993;234:156-64 pubmed publisher
    ..Freshly formed benzamidine crystals were found to provide a suitable nucleation surface for crystallisation of bacteriorhodopsin. At 20 degrees C and 1% octylglucoside pseudohexagonal needles of bacteriorhodopsin nucleated on the ..
  9. Henderson R, Baldwin J, Ceska T, Zemlin F, Beckmann E, Downing K. Model for the structure of bacteriorhodopsin based on high-resolution electron cryo-microscopy. J Mol Biol. 1990;213:899-929 pubmed publisher
    The light-driven proton pump bacteriorhodopsin occurs naturally as two-dimensional crystals...

More Information

Publications66

  1. Ceska T, Henderson R. Analysis of high-resolution electron diffraction patterns from purple membrane labelled with heavy-atoms. J Mol Biol. 1990;213:539-60 pubmed publisher
    Progress in the structure determination of bacteriorhodopsin, the protein component of purple membrane from Halobacterium halobium has been limited by the lack of three-dimensional phase information between 6 and 3 A resolution...
  2. Whitelegge J, Gundersen C, Faull K. Electrospray-ionization mass spectrometry of intact intrinsic membrane proteins. Protein Sci. 1998;7:1423-30 pubmed publisher
    ..The spectra of four examples, bacteriorhodopsin and its apoprotein from Halobacterium and the D1 and D2 reaction-center subunits from spinach thylakoids, ..
  3. Grigorieff N, Ceska T, Downing K, Baldwin J, Henderson R. Electron-crystallographic refinement of the structure of bacteriorhodopsin. J Mol Biol. 1996;259:393-421 pubmed publisher
    ..from 30 new images of tilted specimens, an improved experimental density map has been calculated for bacteriorhodopsin. The atomic model has then been rebuilt into this new map with particular attention to the surface loops...
  4. Faham S, Boulting G, Massey E, Yohannan S, Yang D, Bowie J. Crystallization of bacteriorhodopsin from bicelle formulations at room temperature. Protein Sci. 2005;14:836-40 pubmed publisher
    We showed previously that high-quality crystals of bacteriorhodopsin (bR) from Halobacterium salinarum can be obtained from bicelle-forming DMPC/CHAPSO mixtures at 37 degrees C...
  5. Okumura H, Murakami M, Kouyama T. Crystal structures of acid blue and alkaline purple forms of bacteriorhodopsin. J Mol Biol. 2005;351:481-95 pubmed publisher
    b>Bacteriorhodopsin, a light-driven proton pump found in the purple membrane of Halobacterium salinarum, exhibits purple at neutral pH but its color is sensitive to pH...
  6. Luecke H, Schobert B, Cartailler J, Richter H, Rosengarth A, Needleman R, et al. Coupling photoisomerization of retinal to directional transport in bacteriorhodopsin. J Mol Biol. 2000;300:1237-55 pubmed publisher
    In order to understand how isomerization of the retinal drives unidirectional transmembrane ion transport in bacteriorhodopsin, we determined the atomic structures of the BR state and M photointermediate of the E204Q mutant, to 1.7 and 1...
  7. Lanyi J, Schobert B. Structural changes in the L photointermediate of bacteriorhodopsin. J Mol Biol. 2007;365:1379-92 pubmed publisher
    The L to M reaction of the bacteriorhodopsin photocycle includes the crucial proton transfer from the retinal Schiff base to Asp85...
  8. Facciotti M, Cheung V, Nguyen D, Rouhani S, Glaeser R. Crystal structure of the bromide-bound D85S mutant of bacteriorhodopsin: principles of ion pumping. Biophys J. 2003;85:451-8 pubmed
    We report the crystal structure of a bromide-bound form of the D85S mutant of bacteriorhodopsin, bR(D85S), a protein that uses light energy rather than ATP to pump halide ions across the cell membrane...
  9. Luecke H, Richter H, Lanyi J. Proton transfer pathways in bacteriorhodopsin at 2.3 angstrom resolution. Science. 1998;280:1934-7 pubmed
    Photoisomerization of the retinal of bacteriorhodopsin initiates a cyclic reaction in which a proton is translocated across the membrane. Studies of this protein promise a better understanding of how ion pumps function...
  10. Yohannan S, Yang D, Faham S, Boulting G, Whitelegge J, Bowie J. Proline substitutions are not easily accommodated in a membrane protein. J Mol Biol. 2004;341:1-6 pubmed publisher
    ..tested this possibility by making proline substitutions at 15 positions throughout the N-terminal half of bacteriorhodopsin helix B...
  11. Sato H, Takeda K, Tani K, Hino T, Okada T, Nakasako M, et al. Specific lipid-protein interactions in a novel honeycomb lattice structure of bacteriorhodopsin. Acta Crystallogr D Biol Crystallogr. 1999;55:1251-6 pubmed
    In the purple membrane of Halobacterium salinarium, bacteriorhodopsin trimers are arranged in a hexagonal lattice...
  12. Essen L, Siegert R, Lehmann W, Oesterhelt D. Lipid patches in membrane protein oligomers: crystal structure of the bacteriorhodopsin-lipid complex. Proc Natl Acad Sci U S A. 1998;95:11673-8 pubmed
    Heterogenous nucleation on small molecule crystals causes a monoclinic crystal form of bacteriorhodopsin (BR) in which trimers of this membrane protein pack differently than in native purple membranes...
  13. Edman K, Royant A, Larsson G, Jacobson F, Taylor T, van der Spoel D, et al. Deformation of helix C in the low temperature L-intermediate of bacteriorhodopsin. J Biol Chem. 2004;279:2147-58 pubmed publisher
    ..analogues, have produced a consistent picture of the structural mechanism of light-driven proton pumping by bacteriorhodopsin. Of central importance within this picture is the structure of the L-intermediate, which follows the retinal ..
  14. Yohannan S, Faham S, Yang D, Grosfeld D, Chamberlain A, Bowie J. A C alpha-H...O hydrogen bond in a membrane protein is not stabilizing. J Am Chem Soc. 2004;126:2284-5 pubmed
    ..O bonds for protein stability. Thr24 in bacteriorhodopsin, which makes an interhelical Calpha-H.....
  15. Lomize A, Pervushin K, Arseniev A. Spatial structure of (34-65)bacterioopsin polypeptide in SDS micelles determined from nuclear magnetic resonance data. J Biomol NMR. 1992;2:361-72 pubmed
    ..The secondary structure of segment B in micelles is consistent with the high-resolution electron cryomicroscopy model of bacteriorhodopsin (Henderson et al. (1990) J. Mol. Biol., 213, 899-929).
  16. Chen D, Wang J, Lanyi J. Electron paramagnetic resonance study of structural changes in the O photointermediate of bacteriorhodopsin. J Mol Biol. 2007;366:790-805 pubmed
    The structural changes of bacteriorhodopsin during its photochemical cycle, as revealed by crystal structures of trapped intermediates, have provided insights to the proton translocation mechanism...
  17. Mitsuoka K, Hirai T, Murata K, Miyazawa A, Kidera A, Kimura Y, et al. The structure of bacteriorhodopsin at 3.0 A resolution based on electron crystallography: implication of the charge distribution. J Mol Biol. 1999;286:861-82 pubmed publisher
    ..work, we observed two different types of densities around acidic residues in the experimental (|Fo|) map of bacteriorhodopsin (bR), a light-driven proton pump...
  18. Matsui Y, Sakai K, Murakami M, Shiro Y, Okumura H, Kouyama T. Specific damage induced by X-ray radiation and structural changes in the primary photoreaction of bacteriorhodopsin. J Mol Biol. 2002;324:469-81 pubmed
    b>Bacteriorhodopsin, the sole membrane protein of the purple membrane of Halobacterium salinarum, functions as a light-driven proton pump...
  19. Faham S, Yang D, Bare E, Yohannan S, Whitelegge J, Bowie J. Side-chain contributions to membrane protein structure and stability. J Mol Biol. 2004;335:297-305 pubmed
    ..To investigate these forces we introduced alanine substitutions at 24 positions in the B helix of bacteriorhodopsin and examined their effects on structure and stability...
  20. Patzelt H, Simon B, terLaak A, Kessler B, K hne R, Schmieder P, et al. The structures of the active center in dark-adapted bacteriorhodopsin by solution-state NMR spectroscopy. Proc Natl Acad Sci U S A. 2002;99:9765-70 pubmed publisher
    The two forms of bacteriorhodopsin present in the dark-adapted state, containing either all-trans or 13-cis,15-syn retinal, were examined by using solution state NMR, and their structures were determined...
  21. Henderson R, Jubb J, Whytock S. Specific labelling of the protein and lipid on the extracellular surface of purple membrane. J Mol Biol. 1978;123:259-74 pubmed
  22. Kouyama T, Nishikawa T, Tokuhisa T, Okumura H. Crystal structure of the L intermediate of bacteriorhodopsin: evidence for vertical translocation of a water molecule during the proton pumping cycle. J Mol Biol. 2004;335:531-46 pubmed
    For structural investigation of the L intermediate of bacteriorhodopsin, a 3D crystal belonging to the space group P622 was illuminated with green light at 160 K and subsequently with red light at 100 K...
  23. Dunn R, Hackett N, Huang K, Jones S, Khorana H, Lee D, et al. Studies on the light-transducing pigment bacteriorhodopsin. Cold Spring Harb Symp Quant Biol. 1983;48 Pt 2:853-62 pubmed
  24. Pervushin K, Arseniev A. Three-dimensional structure of (1-36)bacterioopsin in methanol-chloroform mixture and SDS micelles determined by 2D 1H-NMR spectroscopy. FEBS Lett. 1992;308:190-6 pubmed
    ..heavy atoms and fit well with Pro8 to Met32 alpha-helical region in electron cryo-microscopy model of bacteriorhodopsin. The N-terminal region Ala2-Gly6 of sA in organic mixture has a fixed structure of two consecutive gamma-..
  25. Barsukov I, Abdulaeva G, Arseniev A, Bystrov V. Sequence-specific 1H-NMR assignment and conformation of proteolytic fragment 163-231 of bacterioopsin. Eur J Biochem. 1990;192:321-7 pubmed
  26. Cieplak M, Filipek S, Janovjak H, Krzy ko K. Pulling single bacteriorhodopsin out of a membrane: Comparison of simulation and experiment. Biochim Biophys Acta. 2006;1758:537-44 pubmed publisher
    ..reproduces the experimentally observed differences between force-extension patterns obtained on bacteriorhodopsin at different temperatures and predicts a lack of symmetry in the choice of the terminus to pull by...
  27. Yohannan S, Faham S, Yang D, Whitelegge J, Bowie J. The evolution of transmembrane helix kinks and the structural diversity of G protein-coupled receptors. Proc Natl Acad Sci U S A. 2004;101:959-63 pubmed publisher
    ..We observe, however, that the three prolines in bacteriorhodopsin transmembrane helices can be changed to alanine with little structural consequences...
  28. Soppa J, Duschl J, Oesterhelt D. Bacterioopsin, haloopsin, and sensory opsin I of the halobacterial isolate Halobacterium sp. strain SG1: three new members of a growing family. J Bacteriol. 1993;175:2720-6 pubmed
    ..These results were in excellent agreement with the structural model of bacteriorhodopsin of Halobacterium halobium as well as with mutant studies, indicating that (i) structure predictions based on ..
  29. Popot J, Engelman D, Gurel O, Zaccai G. Tertiary structure of bacteriorhodopsin. Positions and orientations of helices A and B in the structural map determined by neutron diffraction. J Mol Biol. 1989;210:829-47 pubmed
    Positions and rotations of two helices in the tertiary structure of bacteriorhodopsin have been studied by neutron diffraction using reconstituted, hybrid purple membrane samples...
  30. Barsukov I, Nolde D, Lomize A, Arseniev A. Three-dimensional structure of proteolytic fragment 163-231 of bacterioopsin determined from nuclear magnetic resonance data in solution. Eur J Biochem. 1992;206:665-72 pubmed
    ..The alpha-helices correspond to transmembrane segments F and G of bacteriorhodopsin. The segment F contains proline 186, which introduces a kink of about 25 degrees with a disruption of the ..
  31. Lanyi J, Schobert B. Crystallographic structure of the retinal and the protein after deprotonation of the Schiff base: the switch in the bacteriorhodopsin photocycle. J Mol Biol. 2002;321:727-37 pubmed
    We illuminated bacteriorhodopsin crystals at 210K to produce, in a photostationary state with 60% occupancy, the earliest M intermediate (M1) of the photocycle...
  32. Royant A, Edman K, Ursby T, Pebay Peyroula E, Landau E, Neutze R. Helix deformation is coupled to vectorial proton transport in the photocycle of bacteriorhodopsin. Nature. 2000;406:645-8 pubmed publisher
    ..b>Bacteriorhodopsin, the simplest known proton pump, provides a paradigm for understanding this process. Here we report, at 2...
  33. Sass H, B ldt G, Gessenich R, Hehn D, Neff D, Schlesinger R, et al. Structural alterations for proton translocation in the M state of wild-type bacteriorhodopsin. Nature. 2000;406:649-53 pubmed publisher
    ..The light-driven proton pump bacteriorhodopsin is the best-characterized protein providing this function...
  34. Dunn R, McCoy J, Simsek M, Majumdar A, Chang S, RajBhandary U, et al. The bacteriorhodopsin gene. Proc Natl Acad Sci U S A. 1981;78:6744-8 pubmed
    The bacteriorhodopsin gene has been identified in a 5.3-kilobase restriction endonuclease fragment isolated from Halobacterium halobium DNA, using a cloned cDNA fragment as the probe...
  35. Schobert B, Cupp Vickery J, Hornak V, Smith S, Lanyi J. Crystallographic structure of the K intermediate of bacteriorhodopsin: conservation of free energy after photoisomerization of the retinal. J Mol Biol. 2002;321:715-26 pubmed
    The K state, an early intermediate of the bacteriorhodopsin photocycle, contains the excess free energy used for light-driven proton transport...
  36. Facciotti M, Cheung V, Lunde C, Rouhani S, Baliga N, Glaeser R. Specificity of anion binding in the substrate pocket of bacteriorhodopsin. Biochemistry. 2004;43:4934-43 pubmed
    The structure of the D85S mutant of bacteriorhodopsin with a nitrate anion bound in the Schiff base binding site and the structure of the anion-free protein have been obtained in the same crystal form...
  37. Nango E, Royant A, Kubo M, Nakane T, Wickstrand C, Kimura T, et al. A three-dimensional movie of structural changes in bacteriorhodopsin. Science. 2016;354:1552-1557 pubmed publisher
    b>Bacteriorhodopsin (bR) is a light-driven proton pump and a model membrane transport protein...
  38. Abdulaeva G, Arseniev A. 1H-15N-NMR studies of bacteriorhodopsin Halobacterium halobium. Conformational dynamics of the four-helical bundle. Eur J Biochem. 1992;210:223-9 pubmed
    ..Less than half of the cross-peaks expected from the amino acid sequence of uniformly 15N-labeled bacteriorhodopsin were observed, using heteronuclear 1H-15N coherence spectroscopy...
  39. Katre N, Wolber P, Stoeckenius W, Stroud R. Attachment site(s) of retinal in bacteriorhodopsin. Proc Natl Acad Sci U S A. 1981;78:4068-72 pubmed
    After chemical reduction of the retinylidene-lysine Schiff base linkage in bacteriorhodopsin, the retinyl residue is covalently attached to Lys-216 (with a possible minor fraction on Lys-172) or to both Lys-216(172) and Lys-40/41...
  40. Lanyi J, Schobert B. Mechanism of proton transport in bacteriorhodopsin from crystallographic structures of the K, L, M1, M2, and M2' intermediates of the photocycle. J Mol Biol. 2003;328:439-50 pubmed
    We produced the L intermediate of the photocycle in a bacteriorhodopsin crystal in photo-stationary state at 170 K with red laser illumination at 60% occupancy, and determined its structure to 1.62 A resolution...
  41. Takeda K, Matsui Y, Kamiya N, Adachi S, Okumura H, Kouyama T. Crystal structure of the M intermediate of bacteriorhodopsin: allosteric structural changes mediated by sliding movement of a transmembrane helix. J Mol Biol. 2004;341:1023-37 pubmed
    Structural changes in the proton pumping cycle of wild-type bacteriorhodopsin were investigated by using a 3D crystal (space group P622)prepared by the membrane fusion method...
  42. Pervushin K, Popov A, Arseniev A. Three-dimensional structure of (1-71)bacterioopsin solubilized in methanol/chloroform and SDS micelles determined by 15N-1H heteronuclear NMR spectroscopy. Eur J Biochem. 1994;219:571-83 pubmed
    ..Using NMR data, along with the electron cryomicroscopy model of bacteriorhodopsin [Henderson, R., Baldwin, J. M., Ceska, T. A., Zemlin, F., Beckman, E. & Downing, K. H. (1990) J. Mol. Biol...
  43. Kamihira M, Watts A. Functionally relevant coupled dynamic profile of bacteriorhodopsin and lipids in purple membranes. Biochemistry. 2006;45:4304-13 pubmed publisher
    The dynamics of bacteriorhodopsin (bR) and the lipid headgroups in oriented purple membranes (PMs) was determined at various temperatures and relative humidity (rh) using solid-state NMR spectroscopy...
  44. Rouhani S, Cartailler J, Facciotti M, Walian P, Needleman R, Lanyi J, et al. Crystal structure of the D85S mutant of bacteriorhodopsin: model of an O-like photocycle intermediate. J Mol Biol. 2001;313:615-28 pubmed publisher
    Crystal structures are reported for the D85S and D85S/F219L mutants of the light-driven proton/hydroxyl-pump bacteriorhodopsin. These mutants crystallize in the orthorhombic C222(1) spacegroup, and provide the first demonstration that ..
  45. Takeda K, Sato H, Hino T, Kono M, Fukuda K, Sakurai I, et al. A novel three-dimensional crystal of bacteriorhodopsin obtained by successive fusion of the vesicular assemblies. J Mol Biol. 1998;283:463-74 pubmed publisher
    When the two-dimensional crystal of bacteriorhodopsin (bR), purple membrane, is incubated at high temperature (32 degreesC) with a small amount of the neutral detergent octylthioglucoside in the presence of the precipitant ammonium ..
  46. Lanyi J, Schobert B. Propagating structural perturbation inside bacteriorhodopsin: crystal structures of the M state and the D96A and T46V mutants. Biochemistry. 2006;45:12003-10 pubmed publisher
    The X-ray diffraction structure of the non-illuminated D96A bacteriorhodopsin mutant reveals structural changes as far away as 15 A from residue 96, at the retinal, Trp-182, Ala-215, and waters 501, 402, and 401...
  47. Seehra J, Khorana H. Bacteriorhodopsin precursor. Characterization and its integration into the purple membrane. J Biol Chem. 1984;259:4187-93 pubmed
    Halobacterium halobium spheroplasts synthesize and accumulate a bacteriorhodopsin precursor...
  48. Ball L, Oatis J, Dharmasiri K, Busman M, Wang J, Cowden L, et al. Mass spectrometric analysis of integral membrane proteins: application to complete mapping of bacteriorhodopsins and rhodopsin. Protein Sci. 1998;7:758-64 pubmed
    ..This method has been applied to wild type (WT) bacteriorhodopsin (bR), cysteine containing mutants of bR, and the prototypical G-protein coupled receptor, rhodopsin (Rh)...
  49. Berger B, Gendron C, Lenhoff A, Kaler E. Effects of additives on surfactant phase behavior relevant to bacteriorhodopsin crystallization. Protein Sci. 2006;15:2682-96 pubmed
    The interactions leading to crystallization of the integral membrane protein bacteriorhodopsin solubilized in n-octyl-beta-D-glucoside were investigated...
  50. Edman K, Nollert P, Royant A, Belrhali H, Pebay Peyroula E, Hajdu J, et al. High-resolution X-ray structure of an early intermediate in the bacteriorhodopsin photocycle. Nature. 1999;401:822-6 pubmed publisher
    b>Bacteriorhodopsin is the simplest known photon-driven proton pump and as such provides a model for the study of a basic function in bioenergetics...
  51. Henderson R, Unwin P. Three-dimensional model of purple membrane obtained by electron microscopy. Nature. 1975;257:28-32 pubmed
    ..Lipid bilayer regions fill the spaces between the protein molecules...
  52. Katragadda M, Alderfer J, Yeagle P. Assembly of a polytopic membrane protein structure from the solution structures of overlapping peptide fragments of bacteriorhodopsin. Biophys J. 2001;81:1029-36 pubmed
    ..structure of membrane proteins has been developed and tested on the integral membrane protein, bacteriorhodopsin, the crystal structure of which had previously been determined...
  53. Pebay Peyroula E, Rummel G, Rosenbusch J, Landau E. X-ray structure of bacteriorhodopsin at 2.5 angstroms from microcrystals grown in lipidic cubic phases. Science. 1997;277:1676-81 pubmed
    ..cubic phases provide a continuous three-dimensional bilayer matrix that facilitates nucleation and growth of bacteriorhodopsin microcrystals. The crystals diffract x-rays isotropically to 2.0 angstroms...
  54. Luecke H, Schobert B, Richter H, Cartailler J, Lanyi J. Structural changes in bacteriorhodopsin during ion transport at 2 angstrom resolution. Science. 1999;286:255-61 pubmed
    Crystal structures of the Asp96 to Asn mutant of the light-driven proton pump bacteriorhodopsin and its M photointermediate produced by illumination at ambient temperature have been determined to 1.8 and 2...
  55. Sobol A, Arseniev A, Abdulaeva G, Musina LYu -, Bystrov V. Sequence-specific resonance assignment and secondary structure of (1-71) bacterioopsin. J Biomol NMR. 1992;2:161-71 pubmed
    ..The N-terminal part of the fragment (Ala2-Gly6) adopts the helical conformation stabilized by 3 hydrogen bonds. ..
  56. Kimura Y, Vassylyev D, Miyazawa A, Kidera A, Matsushima M, Mitsuoka K, et al. Surface of bacteriorhodopsin revealed by high-resolution electron crystallography. Nature. 1997;389:206-11 pubmed publisher
    b>Bacteriorhodopsin is a transmembrane protein that uses light energy, absorbed by its chromophore retinal, to pump protons from the cytoplasm of bacteria such as Halobacterium salinarium into the extracellular space...
  57. Schobert B, Brown L, Lanyi J. Crystallographic structures of the M and N intermediates of bacteriorhodopsin: assembly of a hydrogen-bonded chain of water molecules between Asp-96 and the retinal Schiff base. J Mol Biol. 2003;330:553-70 pubmed
    An M intermediate of wild-type bacteriorhodopsin and an N intermediate of the V49A mutant were accumulated in photostationary states at pH 5.6 and 295 K, and their crystal structures determined to 1.52A and 1.62A resolution, respectively...