2OHA

Myoglobin cavity mutant F138W


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.166 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Ligand pathways in myoglobin: A review of trp cavity mutations.

Olson, J.S.Soman, J.Phillips, G.N.

(2007) Iubmb Life 59: 552-562

  • DOI: 10.1080/15216540701230495
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The pathways for ligand entry and exit in myoglobin have now been well established by a wide variety of experimental results, including pico- to nano- to microsecond transient absorbance measurements and time-resolved X-ray crystallographic measureme ...

    The pathways for ligand entry and exit in myoglobin have now been well established by a wide variety of experimental results, including pico- to nano- to microsecond transient absorbance measurements and time-resolved X-ray crystallographic measurements. Trp insertions have been used to block, one at a time, the three major cavities occupied by photodissociated ligands. In this work, we review the effects of the L29(B10)W mutation, which places a large indole ring in the initial 'docking site' for photodissociated ligands. Then, the effects of blocking the Xe4 site with I28W, V68W, and I107W mutations and the Xe1 cavity with L89W, L104W, and F138W mutations are described. The structures of four of these mutants are shown for the first time (Trp28, Trp68, Trp107, and Trp 138 sperm whale metMb). All available results support a 'side path' mechanism in which ligands move into and out of myoglobin by outward rotation of the HisE7 side chain, but after entry can migrate into internal cavities, including the distal Xe4 and proximal Xe1 binding sites. The distal cavities act like the pocket of a baseball glove, catching the ligand and holding it long enough for the histidine gate to close and facilitate internal coordination with the heme iron atom. The physiological role of the proximal Xe1 site is less clear because changes in the size of this cavity have minimal effects on overall O(2) binding parameters.


    Organizational Affiliation

    Department of Biochemistry & Cell Biology, Rice University, Texas 77005-1892, USA. olson@rice.ed




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Myoglobin
A
154Physeter catodonMutation(s): 1 
Gene Names: MB
Find proteins for P02185 (Physeter catodon)
Go to Gene View: MB
Go to UniProtKB:  P02185
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
HEM
Query on HEM

Download SDF File 
Download CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.166 
  • Space Group: P 6
Unit Cell:
Length (Å)Angle (°)
a = 90.180α = 90.00
b = 90.180β = 90.00
c = 45.340γ = 120.00
Software Package:
Software NamePurpose
d*TREKdata processing
CNSrefinement
PDB_EXTRACTdata extraction
d*TREKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-01-23
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance