1shi: Difference between revisions
New page: left|200px<br /><applet load="1shi" size="450" color="white" frame="true" align="right" spinBox="true" caption="1shi" /> '''REFINED STRUCTURE IN SOLUTION OF THE SEA ANE... |
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[[Image:1shi.gif|left|200px]]<br /><applet load="1shi" size=" | [[Image:1shi.gif|left|200px]]<br /><applet load="1shi" size="350" color="white" frame="true" align="right" spinBox="true" | ||
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'''REFINED STRUCTURE IN SOLUTION OF THE SEA ANEMONE NEUROTOXIN SHI'''<br /> | '''REFINED STRUCTURE IN SOLUTION OF THE SEA ANEMONE NEUROTOXIN SHI'''<br /> | ||
==Overview== | ==Overview== | ||
A high resolution structure in solution has been determined for the | A high resolution structure in solution has been determined for the polypeptide neurotoxin I, from the sea anemone Stichodactyla helianthus, using NMR data, distance geometry calculations, and refinement by back-calculation of two-dimensional nuclear Overhauser enhancement (NOE) spectra. A set of 913 distance constraints derived from NOEs was used, together with a large set of lower distance bounds based on the absence of NOEs in the spectrum. Eight published structures for neurotoxin I were refined independently to give structures which agree better with the experimental data, as reflected in reduced R factors calculated over well resolved cross-peaks of the two-dimensional NOE spectra and a lower total volume of peaks in back-calculated spectra that are absent from experimental spectra. The refined structures are also more precisely defined, with mean pairwise root mean square differences over backbone heavy atoms of 0.62 A for well defined residues and 1.14 A for all residues, compared with previous values of 1.09 and 2.41 A, respectively. The consensus constraint set from the 8 refined structures was also used to generate 12 new structures, with corresponding root mean square differences of 0.76 and 1.26 A. In all 20 structures the loop linking the first and second strands of the beta-sheet is considerably better defined than before. A type I beta-turn encompassing the functionally important residues Asp6, Asp7, and Glu8 is evident in the refined structures. | ||
==About this Structure== | ==About this Structure== | ||
1SHI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Stichodactyla_helianthus Stichodactyla helianthus] with NH2 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 1SHI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Stichodactyla_helianthus Stichodactyla helianthus] with <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SHI OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Stichodactyla helianthus]] | [[Category: Stichodactyla helianthus]] | ||
[[Category: Dyke, T | [[Category: Dyke, T R.]] | ||
[[Category: Norton, R | [[Category: Norton, R S.]] | ||
[[Category: Pallaghy, P | [[Category: Pallaghy, P K.]] | ||
[[Category: NH2]] | [[Category: NH2]] | ||
[[Category: neurotoxin]] | [[Category: neurotoxin]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:01:32 2008'' | ||
Revision as of 16:01, 21 February 2008
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REFINED STRUCTURE IN SOLUTION OF THE SEA ANEMONE NEUROTOXIN SHI
OverviewOverview
A high resolution structure in solution has been determined for the polypeptide neurotoxin I, from the sea anemone Stichodactyla helianthus, using NMR data, distance geometry calculations, and refinement by back-calculation of two-dimensional nuclear Overhauser enhancement (NOE) spectra. A set of 913 distance constraints derived from NOEs was used, together with a large set of lower distance bounds based on the absence of NOEs in the spectrum. Eight published structures for neurotoxin I were refined independently to give structures which agree better with the experimental data, as reflected in reduced R factors calculated over well resolved cross-peaks of the two-dimensional NOE spectra and a lower total volume of peaks in back-calculated spectra that are absent from experimental spectra. The refined structures are also more precisely defined, with mean pairwise root mean square differences over backbone heavy atoms of 0.62 A for well defined residues and 1.14 A for all residues, compared with previous values of 1.09 and 2.41 A, respectively. The consensus constraint set from the 8 refined structures was also used to generate 12 new structures, with corresponding root mean square differences of 0.76 and 1.26 A. In all 20 structures the loop linking the first and second strands of the beta-sheet is considerably better defined than before. A type I beta-turn encompassing the functionally important residues Asp6, Asp7, and Glu8 is evident in the refined structures.
About this StructureAbout this Structure
1SHI is a Single protein structure of sequence from Stichodactyla helianthus with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Refined structure in solution of the sea anemone neurotoxin ShI., Wilcox GR, Fogh RH, Norton RS, J Biol Chem. 1993 Nov 25;268(33):24707-19. PMID:7901218
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