2G12: Photolyzed Co L29f Myoglobin: 316ns

Picosecond time-resolved crystallography was used to follow the dissociation of carbon monoxide from the heme pocket of a mutant sperm whale myoglobin and the resultant conformational changes. Electron-density maps have previously been created at various time points and used to describe amino-acid side-chain and carbon monoxide movements. In this work, difference refinement was employed to generate atomic coordinates at each time point in order to create a more explicit quantitative representation of the photo-dissociation process. After photolysis the carbon monoxide moves to a docking site, causing rearrangements in the heme-pocket residues, the coordinate changes of which can be plotted as a function of time. These include rotations of the heme-pocket phenylalanine concomitant with movement of the distal histidine toward the solvent, potentially allowing carbon monoxide movement in and out of the protein and proximal displacement of the heme iron. The degree of relaxation toward the intermediate and deoxy states was probed by analysis of the coordinate movements in the time-resolved models, revealing a non-linear progression toward the unbound state with coordinate movements that begin in the heme-pocket area and then propagate throughout the rest of the protein.
PDB ID: 2G12Download
MMDB ID: 39918
PDB Deposition Date: 2006/2/13
Updated in MMDB: 2007/11
Experimental Method:
x-ray diffraction
Resolution: 1.9  Å
Source Organism:
Similar Structures:
Biological Unit for 2G12: monomeric; determined by author
Molecular Components in 2G12
Label Count Molecule
Protein (1 molecule)
Molecule annotation
Chemicals (3 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB