1f70: Difference between revisions

Revision as of 13:35, 21 February 2008

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 Thu Feb 21 12:35:34 2008

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OCA

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-[[Image:1f70.jpg|left|200px]]<br /><applet load="1f70" size="450" color="white" frame="true" align="right" spinBox="true"
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 caption="1f70" />
 '''REFINED SOLUTION STRUCTURE OF CALMODULIN N-TERMINAL DOMAIN'''<br />
 ==Overview==
-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.
+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 Structure==
-F70 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1F70 OCA].
+F70 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F70 OCA].
 ==Reference==
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