2G0S

Unphotolyzed CO-bound L29F Myoglobin, crystal 2

Summary for 2G0S

• Entry DOI: 10.2210/pdb2g0s/pdb
• Descriptor: Myoglobin, SULFATE ION, PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• Functional Keywords: time-resolved crystallography; myoglobin; difference refinement; structure-function relationship; intermediate states, transport protein
• Biological source: Physeter catodon (sperm whale)
• Total number of polymer chains: 1
• Total formula weight: 18139.74

Authors

Aranda, R.,Levin, E.J.,Schotte, F.,Anfinrud, P.A.,Phillips Jr., G.N. (deposition date: 2006-02-13, release date: 2006-07-04, Last modification date: 2023-08-30)

Primary citation

Aranda, R.,Levin, E.J.,Schotte, F.,Anfinrud, P.A.,Phillips Jr., G.N.
Time-dependent atomic coordinates for the dissociation of carbon monoxide from myoglobin.
Acta Crystallogr.,Sect.D, 62:776-783, 2006

PubMed Abstract: 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.

PubMed: 16790933
DOI: 10.1107/S0907444906017318

Experimental method

X-RAY DIFFRACTION (1.9 Å)