1IW9

Crystal Structure of the M Intermediate of Bacteriorhodopsin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.224 
  • R-Value Observed: 0.224 

wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Crystal structure of the M intermediate of bacteriorhodopsin: allosteric structural changes mediated by sliding movement of a transmembrane helix

Takeda, K.Matsui, Y.Kamiya, N.Adachi, S.Okumura, H.Kouyama, T.

(2004) J Mol Biol 341: 1023-1037

  • DOI: https://doi.org/10.1016/j.jmb.2004.06.080
  • Primary Citation of Related Structures:  
    1DZE, 1IW9

  • PubMed Abstract: 

    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. Protein-protein contacts in the crystal elongate the lifetime of the M intermediate by a factor of approximately 100,allowing high levels of the M intermediate to accumulate under continuous illumination. When the M intermediate generated at room temperature was exposed to a low flux of X-rays (approximately 10(14) photons/mm2), this yellow intermediate was converted into a blue species having an absorption maximum at 650 nm. This color change is suggested to accompany a configuration change in the retinal-Lys216 chain. The true conformational change associated with formation of the M intermediate was analyzed by taking the X-radiation-induced structural change into account. Our result indicates that, upon formation of the M intermediate, helix G move stowards the extra-cellular side by, on average, 0.5 angstroms. This movement is coupled with several reactions occurring at distal sites in the protein: (1) reorientation of the side-chain of Leu93 contacting the C13 methyl group of retinal, which is accompanied by detachment of a water molecule from the Schiff base; (2) a significant distortion in the F-G loop, triggering destruction of a hydrogen bonding interaction between a pair of glutamate groups (Glu194 and Glu204); (3) formation of a salt bridge between the carboxylate group of Glu204 and the guanidinium ion of Arg82, which is accompanied by a large distortion in the extra-cellular half of helix C; (4)noticeable movements of the AB loop and the cytoplasmic end of helix B. But, no appreciable change is induced in the peptide backbone of helices A,D, E and F. These structural changes are discussed from the viewpoint of translocation of water molecules.


  • Organizational Affiliation

    Department of Physics, Graduate School of Science, Nagoya University, Japan.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
bacteriorhodopsin248Halobacterium salinarumMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P02945 (Halobacterium salinarum (strain ATCC 700922 / JCM 11081 / NRC-1))
Explore P02945 
Go to UniProtKB:  P02945
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02945
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
beta-D-galactopyranose-(1-6)-alpha-D-mannopyranose-(1-2)-alpha-D-glucopyranose
B
3N/A
Glycosylation Resources
GlyTouCan:  G59827MO
GlyCosmos:  G59827MO
GlyGen:  G59827MO
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.224 
  • R-Value Observed: 0.224 
  • Space Group: P 6 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 102.3α = 90
b = 102.3β = 90
c = 112.3γ = 120
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
CNSrefinement
CCP4data scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-12-23
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2023-10-25
    Changes: Advisory, Data collection, Database references, Refinement description, Structure summary