2grf
Crystal structure of Scapharca inaequivalvis HBI, M37V mutant in the absence of ligandCrystal structure of Scapharca inaequivalvis HBI, M37V mutant in the absence of ligand
Structural highlights
FunctionEvolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedProtein allostery provides mechanisms for regulation of biological function at the molecular level. We present here an investigation of global, ligand-induced allosteric transition in a protein by time-resolved x-ray diffraction. The study provides a view of structural changes in single crystals of Scapharca dimeric hemoglobin as they proceed in real time, from 5 ns to 80 micros after ligand photodissociation. A tertiary intermediate structure forms rapidly (<5 ns) as the protein responds to the presence of an unliganded heme within each R-state protein subunit, with key structural changes observed in the heme groups, neighboring residues, and interface water molecules. This intermediate lays a foundation for the concerted tertiary and quaternary structural changes that occur on a microsecond time scale and are associated with the transition to a low-affinity T-state structure. Reversal of these changes shows a considerable lag as a T-like structure persists well after ligand rebinding, suggesting a slow T-to-R transition. Allosteric action in real time: time-resolved crystallographic studies of a cooperative dimeric hemoglobin.,Knapp JE, Pahl R, Srajer V, Royer WE Jr Proc Natl Acad Sci U S A. 2006 May 16;103(20):7649-54. Epub 2006 May 9. PMID:16684887[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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