1BRD

Model for the structure of Bacteriorhodopsin based on high-resolution Electron Cryo-microscopy


Experimental Data Snapshot

  • Method: ELECTRON CRYSTALLOGRAPHY
  • Resolution: 3.5 Å
  • Aggregation State: 2D ARRAY 
  • Reconstruction Method: CRYSTALLOGRAPHY 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Model for the structure of bacteriorhodopsin based on high-resolution electron cryo-microscopy.

Henderson, R.Baldwin, J.M.Ceska, T.A.Zemlin, F.Beckmann, E.Downing, K.H.

(1990) J.Mol.Biol. 213: 899-929

  • DOI: 10.1016/S0022-2836(05)80271-2

  • PubMed Abstract: 
  • The light-driven proton pump bacteriorhodopsin occurs naturally as two-dimensional crystals. A three-dimensional density map of the structure, at near-atomic resolution, has been obtained by studying the crystals using electron cryo-microscopy to obt ...

    The light-driven proton pump bacteriorhodopsin occurs naturally as two-dimensional crystals. A three-dimensional density map of the structure, at near-atomic resolution, has been obtained by studying the crystals using electron cryo-microscopy to obtain electron diffraction patterns and high-resolution micrographs. New methods were developed for analysing micrographs from tilted specimens, incorporating methods previously developed for untilted specimens that enable large areas to be analysed and corrected for distortions. Data from 72 images, from both tilted and untilted specimens, were analysed to produce the phases of 2700 independent Fourier components of the structure. The amplitudes of these components were accurately measured from 150 diffraction patterns. Together, these data represent about half of the full three-dimensional transform to 3.5 A. The map of the structure has a resolution of 3.5 A in a direction parallel to the membrane plane but lower than this in the perpendicular direction. It shows many features in the density that are resolved from the main density of the seven alpha-helices. We interpret these features as the bulky aromatic side-chains of phenylalanine, tyrosine and tryptophan residues. There is also a very dense feature, which is the beta-ionone ring of the retinal chromophore. Using these bulky side-chains as guide points and taking account of bulges in the helices that indicate smaller side-chains such as leucine, a complete atomic model for bacteriorhodopsin between amino acid residues 8 and 225 has been built. There are 21 amino acid residues, contributed by all seven helices, surrounding the retinal and 26 residues, contributed by five helices, forming the proton pathway or channel. Ten of the amino acid residues in the middle of the proton channel are also part of the retinal binding site. The model also provides a useful basis for consideration of the mechanism of proton pumping and allows a consistent interpretation of a great deal of other experimental data. In particular, the structure suggests that pK changes in the Schiff base must act as the means by which light energy is converted into proton pumping pressure in the channel. Asp96 is on the pathway from the cytoplasm to the Schiff base and Asp85 is on the pathway from the Schiff base to the extracellular surface.


    Related Citations: 
    • Three-Dimensional Model of Purple Membrane Obtained by Electron Microscopy
      Henderson, R.,Unwin, P.N.T.
      (1975) Nature 257: 28
    • Specific Labelling of the Protein and Lipid on the Extracellular Surface of Purple Membrane
      Henderson, R.,Jubb, J.S.,Whytock, S.
      (1978) J.Mol.Biol. 123: 259


    Organizational Affiliation

    MRC Laboratory of Molecular Biology, Cambridge, U.K.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BACTERIORHODOPSIN PRECURSOR
A
248Halobacterium salinarum (strain ATCC 700922 / JCM 11081 / NRC-1)Gene Names: bop
Find proteins for P02945 (Halobacterium salinarum (strain ATCC 700922 / JCM 11081 / NRC-1))
Go to UniProtKB:  P02945
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
RET
Query on RET

Download SDF File 
Download CCD File 
A
RETINAL
C20 H28 O
NCYCYZXNIZJOKI-OVSJKPMPSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PCA
Query on PCA
A
L-PEPTIDE LINKINGC5 H7 N O3GLU
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON CRYSTALLOGRAPHY
  • Resolution: 3.5 Å
  • Aggregation State: 2D ARRAY 
  • Reconstruction Method: CRYSTALLOGRAPHY 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1991-04-15
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance