1F50

BACTERIORHODOPSIN-BR STATE OF THE E204Q MUTANT AT 1.7 ANGSTROM RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.132 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Coupling photoisomerization of retinal to directional transport in bacteriorhodopsin.

Luecke, H.Schobert, B.Cartailler, J.P.Richter, H.T.Rosengarth, A.Needleman, R.Lanyi, J.K.

(2000) J Mol Biol 300: 1237-1255

  • DOI: 10.1006/jmbi.2000.3884
  • Primary Citation of Related Structures:  
    1F50, 1F4Z

  • PubMed Abstract: 
  • 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 1.8 A resolution, respectively ...

    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 1.8 A resolution, respectively. Comparison of this M, in which proton release to the extracellular surface is blocked, with the previously determined M in the D96N mutant indicates that the changes in the extracellular region are initiated by changes in the electrostatic interactions of the retinal Schiff base with Asp85 and Asp212, but those on the cytoplasmic side originate from steric conflict of the 13-methyl retinal group with Trp182 and distortion of the pi-bulge of helix G. The structural changes suggest that protonation of Asp85 initiates a cascade of atomic displacements in the extracellular region that cause release of a proton to the surface. The progressive relaxation of the strained 13-cis retinal chain with deprotonated Schiff base, in turn, initiates atomic displacements in the cytoplasmic region that cause the intercalation of a hydrogen-bonded water molecule between Thr46 and Asp96. This accounts for the lowering of the pK(a) of Asp96, which then reprotonates the Schiff base via a newly formed chain of water molecules that is extending toward the Schiff base.


    Organizational Affiliation

    Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
BACTERIORHODOPSINA227Halobacterium salinarumMutation(s): 1 
Find proteins for P02945 (Halobacterium salinarum (strain ATCC 700922 / JCM 11081 / NRC-1))
Explore P02945 
Go to UniProtKB:  P02945
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
LI1
Query on LI1

Download CCD File 
A
1-[2,6,10.14-TETRAMETHYL-HEXADECAN-16-YL]-2-[2,10,14-TRIMETHYLHEXADECAN-16-YL]GLYCEROL
C42 H86 O3
YERVUJAKCNBGCR-BIHSMRAKSA-N
 Ligand Interaction
SQU
Query on SQU

Download CCD File 
A
2,10,23-TRIMETHYL-TETRACOSANE
C27 H56
ZADHKSJXSZBQFB-HHHXNRCGSA-N
 Ligand Interaction
RET
Query on RET

Download CCD File 
A
RETINAL
C20 H28 O
NCYCYZXNIZJOKI-OVSJKPMPSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.132 
  • Space Group: P 63
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.631α = 90
b = 60.631β = 90
c = 108.156γ = 120
Software Package:
Software NamePurpose
SHELXL-97refinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-08-09
    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