1f70
REFINED SOLUTION STRUCTURE OF CALMODULIN N-TERMINAL DOMAIN
|
OverviewOverview
For an increasing fraction of proteins whose structures are being studied, sequence homology to known structures permits building of low resolution, structural models. It is demonstrated that dipolar couplings, measured in, a liquid crystalline medium, not only can validate such structural models, but also refine them. Here, experimental 1H-15N, 1Halpha-13Calpha, and, 13C'-13Calpha dipolar couplings are shown to decrease the backbone rmsd, between various homology models of calmodulin (CaM) and its crystal, structure. Starting from a model of the Ca2+-saturated C-terminal domain, of CaM, built from the structure of Ca2+-free recoverin on the basis of, remote sequence homology, dipolar couplings are used to decrease the rmsd, between the model and the crystal structure from 5.0 to 1.25 A. A better, starting model, built from the crystal structure of Ca2+-saturated, parvalbumin, decreases in rmsd from 1.25 to 0.93 A. Similarly, starting, from the structure of the Ca2+-ligated CaM N-terminal domain, experimental, dipolar couplings measured for the Ca2+-free form decrease the backbone, rmsd relative to the refined solution structure of apo-CaM from 4.2 to 1.0, A.
About this StructureAbout this Structure
1F70 is a Single protein structure of sequence from Xenopus laevis. Full crystallographic information is available from OCA.
ReferenceReference
Study of conformational rearrangement and refinement of structural homology models by the use of heteronuclear dipolar couplings., Chou JJ, Li S, Bax A, J Biomol NMR. 2000 Nov;18(3):217-27. PMID:11142512
Page seeded by OCA on Tue Nov 20 14:40:00 2007