Crystal structure of oxygenated Scapharca dimeric hemoglobin at 1.7-A resolution

The crystal structure of the cooperative dimeric hemoglobin from the blood clam Scapharca inaequivalvis has been determined in the oxygenated state and refined to an R-factor of 0.157 at 1.7-A resolution. The structure is very similar to the carbon monoxide-liganded form with subtle differences in l...

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Bibliographic Details
Main Authors: Condon, Peter J., Royer, William E.
Other Authors: Department of Biochemistry and Molecular Pharmacology, Program in Molecular Medicine
Format: Article in Journal/Newspaper
Language:English
Published: 2022
Subjects:
Animals
Binding Sites
Bivalvia
Computer Simulation
Crystallography
X-Ray
Heme
Hemoglobins
Ligands
Models
Molecular
Oxyhemoglobins
Protein Conformation
Water
Life Sciences
Medicine and Health Sciences
Sperm whale
Online Access:https://hdl.handle.net/20.500.14038/42471
https://escholarship.umassmed.edu/oapubs/817
Description
Summary:The crystal structure of the cooperative dimeric hemoglobin from the blood clam Scapharca inaequivalvis has been determined in the oxygenated state and refined to an R-factor of 0.157 at 1.7-A resolution. The structure is very similar to the carbon monoxide-liganded form with subtle differences in ligand binding geometry. Oxygen binds to the heme iron in a bent conformation with Fe-O-O angles of 135 degrees and 150 degrees for the two subunits. These observed angles are lower than the equivalent angles in the carbon monoxide-liganded form and intermediate between the angles observed in structures of oxygenated sperm whale myoglobin and oxygenated human hemoglobin. This third high resolution structure of Scapharca dimeric hemoglobin permits a detailed analysis of the water structure in the highly hydrated interface between subunits.

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