2grf
Crystal structure of Scapharca inaequivalvis HBI, M37V mutant in the absence of ligand
| |||||||
| , resolution 2.10Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
Protein 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.
About this StructureAbout this Structure
2GRF is a Single protein structure of sequence from Scapharca inaequivalvis. Full crystallographic information is available from OCA.
ReferenceReference
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
Page seeded by OCA on Thu Mar 20 17:08:06 2008