Ground state of halorhodopsin T203V

Experimental Data Snapshot

  • Resolution: 1.70 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.238 
  • R-Value Observed: 0.238 

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This is version 1.5 of the entry. See complete history


The crystal structure of the L1 intermediate of halorhodopsin at 1.9 angstroms resolution.

Gmelin, W.Zeth, K.Efremov, R.Heberle, J.Tittor, J.Oesterhelt, D.

(2007) Photochem Photobiol 83: 369-377

  • DOI: https://doi.org/10.1562/2006-06-23-RA-947
  • Primary Citation of Related Structures:  
    2JAF, 2JAG

  • PubMed Abstract: 

    The mutant T203V of the light driven chloride pump halorhodopsin from Halobacterium salinarum was crystallized and the X-ray structure was solved at 1.6 angstroms resolution. The T203V structure turned out to be nearly identical to the wild type protein with a root mean square deviation of 0.43 angstroms for the carbon alpha atoms of the protein backbone. Two chloride binding (CB) sites were demonstrated by a substitution of chloride with bromide and an analysis of anomalous difference Fourier maps. The CB1 site was found at the same position as in the wild type structure. In addition, a second chloride binding site CB2 was identified around Q105 due to higher resolution in the mutant crystal. As T203V showed a 10 times slower decay of its photocycle intermediate L, this intermediate could be trapped with an occupancy of 60% upon illumination at room temperature and subsequent cooling to 120 degrees K. Fourier transform infrared spectroscopy clearly identified the crystal to be trapped in the L1 intermediate state and the X-ray structure was solved to 1.9 angstroms resolution. In this intermediate, the chloride moved by 0.3 angstroms within binding site CB1 as indicated by peaks in difference Fourier density maps. The chloride in the second binding site CB2 remained unchanged. Thus, intraproteinous chloride translocation from the extracellular to the cytoplasmic part of the protein must occur in reaction steps following the L1 intermediate in the catalytic cycle of halorhodopsin.

  • Organizational Affiliation

    Max Planck Institute of Biochemistry, Department of Membrane Biochemistry, Martinsried, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Halorhodopsin274Halobacterium salinarum R1Mutation(s): 2 
Gene Names: hopOE_1299R
Membrane Entity: Yes 
Find proteins for B0R2U4 (Halobacterium salinarum (strain ATCC 29341 / DSM 671 / R1))
Explore B0R2U4 
Go to UniProtKB:  B0R2U4
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupB0R2U4
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.70 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.238 
  • R-Value Observed: 0.238 
  • Space Group: H 3 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 94.473α = 90
b = 94.473β = 90
c = 157.137γ = 120
Software Package:
Software NamePurpose
XDSdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-12-14
    Type: Initial release
  • Version 1.1: 2011-12-28
    Changes: Database references, Derived calculations, Non-polymer description, Other, Refinement description, Version format compliance
  • Version 1.2: 2018-11-21
    Changes: Data collection, Database references, Source and taxonomy, Structure summary
  • Version 1.3: 2019-05-22
    Changes: Data collection, Derived calculations, Experimental preparation
  • Version 1.4: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary
  • Version 1.5: 2023-12-13
    Changes: Data collection, Database references, Refinement description, Structure summary