1PXS

Structure of Met56Ala mutant of Bacteriorhodopsin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Side-chain Contributions to Membrane Protein Structure and Stability.

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

(2004) J.Mol.Biol. 335: 297-305

  • Primary Citation of Related Structures:  1PXR, 1PY6

  • PubMed Abstract: 
  • The molecular forces that stabilize membrane protein structure are poorly understood. To investigate these forces we introduced alanine substitutions at 24 positions in the B helix of bacteriorhodopsin and examined their effects on structure and stab ...

    The molecular forces that stabilize membrane protein structure are poorly understood. To investigate these forces we introduced alanine substitutions at 24 positions in the B helix of bacteriorhodopsin and examined their effects on structure and stability. Although most of the results can be rationalized in terms of the folded structure, there are a number of surprises. (1) We find a remarkably high frequency of stabilizing mutations (17%), indicating that membrane proteins are not highly optimized for stability. (2) Helix B is kinked, with the kink centered around Pro50. The P50A mutation has no effect on stability, however, and a crystal structure reveals that the helix remains bent, indicating that tertiary contacts dominate in the distortion of this helix. (3) We find that the protein is stabilized by about 1kcal/mol for every 38A(2) of surface area buried, which is quite similar to soluble proteins in spite of their dramatically different environments. (4) We find little energetic difference, on average, in the burial of apolar surface or polar surface area, implying that van der Waals packing is the dominant force that drives membrane protein folding.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, UCLA-DOE Center for Genomics and Proteomics, Molecular Biology Institute, University of California, Los Angeles, CA 90095-1570, 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: 2.2 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.198 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 44.624α = 90.00
b = 109.662β = 113.50
c = 55.873γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
CNSphasing
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-12-16
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance