1Q5I

Crystal structure of bacteriorhodopsin mutant P186A crystallized from bicelles


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.194 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

The evolution of transmembrane helix kinks and the structural diversity of G protein-coupled receptors.

Yohannan, S.Faham, S.Yang, D.Whitelegge, J.P.Bowie, J.U.

(2004) Proc.Natl.Acad.Sci.USA 101: 959-963

  • DOI: 10.1073/pnas.0306077101
  • Primary Citation of Related Structures:  1Q5J

  • PubMed Abstract: 
  • One of the hallmarks of membrane protein structure is the high frequency of transmembrane helix kinks, which commonly occur at proline residues. Because the proline side chain usually precludes normal helix geometry, it is reasonable to expect that p ...

    One of the hallmarks of membrane protein structure is the high frequency of transmembrane helix kinks, which commonly occur at proline residues. Because the proline side chain usually precludes normal helix geometry, it is reasonable to expect that proline residues generate these kinks. We observe, however, that the three prolines in bacteriorhodopsin transmembrane helices can be changed to alanine with little structural consequences. This finding leads to a conundrum: if proline is not required for helix bending, why are prolines commonly present at bends in transmembrane helices? We propose an evolutionary hypothesis in which a mutation to proline initially induces the kink. The resulting packing defects are later repaired by further mutation, thereby locking the kink in the structure. Thus, most prolines in extant proteins can be removed without major structural consequences. We further propose that nonproline kinks are places where vestigial prolines were later removed during evolution. Consistent with this hypothesis, at 14 of 17 nonproline kinks in membrane proteins of known structure, we find prolines in homologous sequences. Our analysis allows us to predict kink positions with >90% reliability. Kink prediction indicates that different G protein-coupled receptor proteins have different kink patterns and therefore different structures.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, UCLA-DOE Institute for Genomics and Proteomics, Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Bacteriorhodopsin
A, B
249Halobacterium 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, B
RETINAL
C20 H28 O
NCYCYZXNIZJOKI-OVSJKPMPSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.194 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 44.629α = 90.00
b = 108.721β = 113.46
c = 56.093γ = 90.00
Software Package:
Software NamePurpose
CNSphasing
SCALEPACKdata scaling
DENZOdata reduction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-01-06
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2018-01-31
    Type: Experimental preparation