Structural transitions upon ligand binding in a cooperative dimeric hemoglobin.

W E Royer; W A Hendrickson; E Chiancone

doi:10.1126/science.2382132

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PubMed · 2382132

Structural transitions upon ligand binding in a cooperative dimeric hemoglobin.

W E Royer·W A Hendrickson·E Chiancone

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Abstract

Comparison of the 2.4 angstrom resolution crystal structures of dimeric clam hemoglobin in the deoxygenated and carbon-monoxide liganded states shows how radically different the structural basis for cooperative oxygen binding is from that operative in mammalian hemoglobins. Heme groups are in direct communication across a novel subunit interface formed by the E and F helices. The conformational changes at this interface that accompany ligand binding are more dramatic at a tertiary level but more subtle at a quaternary level than those in mammalian hemoglobins. These findings suggest a cooperative mechanism that links ligation at one subunit with potentiation of affinity at the second subunit.

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Amino Acid Sequence Animals Carboxyhemoglobin Hemoglobins Ligands Macromolecular Substances Models, Molecular Molecular Sequence Data Mollusca Protein Conformation Journal Article Research Support, U.S. Gov't, Non-P.H.S.

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W E Royer, W A Hendrickson, E Chiancone. 1990-08-03. Structural transitions upon ligand binding in a cooperative dimeric hemoglobin.. https://doi.org/10.1126/science.2382132

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