+Open data
-Basic information
Entry | Database: PDB / ID: 2brd | |||||||||
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Title | CRYSTAL STRUCTURE OF BACTERIORHODOPSIN IN PURPLE MEMBRANE | |||||||||
Components | BACTERIORHODOPSIN | |||||||||
Keywords | PHOTORECEPTOR / PROTON PUMP / MEMBRANE PROTEIN / RETINAL PROTEIN / TWO-DIMENSIONAL CRYSTAL | |||||||||
Function / homology | Function and homology information light-driven active monoatomic ion transmembrane transporter activity / photoreceptor activity / phototransduction / monoatomic ion channel activity / proton transmembrane transport / plasma membrane Similarity search - Function | |||||||||
Biological species | Halobacterium salinarum (Halophile) | |||||||||
Method | ELECTRON CRYSTALLOGRAPHY / electron crystallography / cryo EM / Resolution: 3.5 Å | |||||||||
Authors | Henderson, R. / Grigorieff, N. | |||||||||
Citation | Journal: J Mol Biol / Year: 1996 Title: Electron-crystallographic refinement of the structure of bacteriorhodopsin. Authors: N Grigorieff / T A Ceska / K H Downing / J M Baldwin / R Henderson / Abstract: Using electron diffraction data corrected for diffuse scattering together with additional phase information from 30 new images of tilted specimens, an improved experimental density map has been ...Using electron diffraction data corrected for diffuse scattering together with additional phase information 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. All the residues from 7 to 227 as well as ten lipid molecules are now included, although a few amino acid residues in three of the six surface loops, about half of the lipid hydrophobic chains and all of the lipid head groups are disordered. The model has then been refined against the experimental diffraction amplitudes to an R-factor of 28% at 3.5 angstrom resolution with strict geometry (0.005 angstrom) bond length deviation) using the improvement of the "free" phase residual between calculated and experimental phases from images as an objective criterion of accuracy. For the refinement some new programs were developed to restrain the number of parameters, to be compatible with the limited resolution of our data. In the final refined model of the protein (2BRD), compared with earlier co-ordinates (1BRD), helix D has been moved towards the cytoplasm by almost 4 angstrom, and the overall accuracy of the co-ordinates of residues in the other six helices has been improved. As a result the positions of nearly all the important residues in bacteriorhodopsin are now well determined. In particular, the buried, protonated Asp115 is 7 angstrom from, and so not in contact with, the retinal and Met118 forms a cap on the pocket occupied by the beta-ionone ring. No clear density exists for the side-chain of Arg82, which forms a central part of the extracellular half-channel. The only arginine side-chain built into good density is that of Arg134 at the extracellular end of helix E, the others being disordered near one of the two surfaces. The interpretation of the end of helix F on the extracellular surface is now clearer; an extra loose helical turn has been built bringing the side-chain of Glu194 close to Arg134 to form a probable salt bridge. The model provides an improved framework for understanding the mechanism of the light-driven proton pumping. A number of cavities that could contain water molecules were found by searching the refined model, most of them above or below the Schiff base in the half-channels leading to the two surfaces. The ordered and disordered regions of the structure are described by the temperature factor distribution. #1: Journal: J.Mol.Biol. / Year: 1990 Title: Analysis of High-Resolution Electron Diffraction Patterns from Purple Membrane Labelled with Heavy-Atoms Authors: Ceska, T.A. / Henderson, R. #2: Journal: J.Mol.Biol. / Year: 1990 Title: Model for the Structure of Bacteriorhodopsin Based on High-Resolution Electron Cryo-Microscopy Authors: Henderson, R. / Baldwin, J.M. / Ceska, T.A. / Zemlin, F. / Beckmann, E. / Downing, K.H. #3: Journal: Nature / Year: 1975 Title: Three-Dimensional Model of Purple Membrane Obtained by Electron Microscopy Authors: Henderson, R. / Unwin, P.N. | |||||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | Molecule: MolmilJmol/JSmol |
-Downloads & links
-Download
PDBx/mmCIF format | 2brd.cif.gz | 70 KB | Display | PDBx/mmCIF format |
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PDB format | pdb2brd.ent.gz | 54.1 KB | Display | PDB format |
PDBx/mmJSON format | 2brd.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 2brd_validation.pdf.gz | 904.3 KB | Display | wwPDB validaton report |
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Full document | 2brd_full_validation.pdf.gz | 942.2 KB | Display | |
Data in XML | 2brd_validation.xml.gz | 14.5 KB | Display | |
Data in CIF | 2brd_validation.cif.gz | 18.1 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/br/2brd ftp://data.pdbj.org/pub/pdb/validation_reports/br/2brd | HTTPS FTP |
-Related structure data
Similar structure data |
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-Links
-Assembly
Deposited unit |
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1 |
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Unit cell |
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-Components
#1: Protein | Mass: 26797.381 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Halobacterium salinarum (Halophile) / Strain: R1 / References: UniProt: P02945 | ||||
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#2: Chemical | ChemComp-DPG / #3: Chemical | ChemComp-RET / | Has protein modification | Y | |
-Experimental details
-Experiment
Experiment | Method: ELECTRON CRYSTALLOGRAPHY |
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EM experiment | Aggregation state: 2D ARRAY / 3D reconstruction method: electron crystallography |
-Sample preparation
Component | Name: BACTERIORHODOPSIN CRYSTAL / Type: COMPLEX |
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Specimen | Embedding applied: YES / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Crystal | Density Matthews: 4.24 Å3/Da / Density % sol: 70.97 % |
Crystal grow | *PLUS Method: other / Details: electron-crystallographic method |
-Data collection
EM imaging | Specimen-ID: 1
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Image recording |
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Diffraction source | Wavelength: 0.033 | ||||||||||||||||||||||||||||||||||||||||
Detector | Detector: FILM / Date: Jan 1, 1986 | ||||||||||||||||||||||||||||||||||||||||
Radiation | Monochromatic (M) / Laue (L): M / Scattering type: electron | ||||||||||||||||||||||||||||||||||||||||
Radiation wavelength | Wavelength: 0.033 Å / Relative weight: 1 | ||||||||||||||||||||||||||||||||||||||||
Reflection | Resolution: 2.8→54 Å / Num. obs: 6750 / % possible obs: 62.3 % / Observed criterion σ(I): 0 / Redundancy: 18 % / Rmerge(I) obs: 0.15 |
-Processing
Software |
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3D reconstruction | Symmetry type: 2D CRYSTAL | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Refinement | Resolution: 3.5→30 Å / σ(F): 0
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Displacement parameters | Biso mean: 114 Å2 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Refinement step | Cycle: LAST / Resolution: 3.5→30 Å
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Refine LS restraints |
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Software | *PLUS Name: PROLSQ / Classification: refinement | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Refinement | *PLUS Rfactor obs: 0.18 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Solvent computation | *PLUS | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Displacement parameters | *PLUS |