1lms
From Proteopedia
(New page: 200px<br /><applet load="1lms" size="450" color="white" frame="true" align="right" spinBox="true" caption="1lms" /> '''Structural model for an alkaline form of fer...) |
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| - | [[Image:1lms.jpg|left|200px]]<br /><applet load="1lms" size=" | + | [[Image:1lms.jpg|left|200px]]<br /><applet load="1lms" size="350" color="white" frame="true" align="right" spinBox="true" |
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'''Structural model for an alkaline form of ferricytochrome c'''<br /> | '''Structural model for an alkaline form of ferricytochrome c'''<br /> | ||
==Overview== | ==Overview== | ||
| - | An (15)N-enriched sample of the yeast iso-1-ferricytochrome c triple | + | An (15)N-enriched sample of the yeast iso-1-ferricytochrome c triple variant (Lys72Ala/Lys79Ala/Cys102Thr) in an alkaline conformation was examined by NMR spectroscopy. The mutations were planned to produce a cytochrome c with a single conformer. Despite suboptimal conditions for the collection of spectra (i.e., pH approximately equal to 11), NMR remains a suitable investigation technique capable of taking advantage of paramagnetism. 76% of amino acids and 49% of protons were assigned successfully. The assignment was in part achieved through standard methods, in part through the identification of groups maintaining the same conformation as in the native protein at pH 7 and, for a few other residues, through a tentative analysis of internuclear distance predictions. Lys73 was assigned as the axial ligand together with His18. In this manner, 838 meaningful NOEs for 108 amino acids, 50 backbone angle constraints, and 203 pseudocontact shifts permitted the convergence of randomly generated structures to a family of conformers with a backbone RMSD of 1.5 +/- 0.2 A. Most of the native cytochrome c conformation is maintained at high pH. The NOE pattern that involves His18 clearly indicates that the proximal side of the protein, including the 20s and 40s loops, remains essentially intact. Structural differences are concentrated in the 70-80 loop, because of the replacement of Met80 by Lys73 as an axial ligand, and in the 50s helix facing that loop; as a consequence, there is increased exposure of the heme group to solvent. Based on several spectral features, we conclude that the folded polypeptide is highly fluxional. |
==About this Structure== | ==About this Structure== | ||
| - | 1LMS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with HEC as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1LMS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=HEC:'>HEC</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LMS OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bertini, I.]] | [[Category: Bertini, I.]] | ||
[[Category: Dolfi, A.]] | [[Category: Dolfi, A.]] | ||
| - | [[Category: Gray, H | + | [[Category: Gray, H B.]] |
| - | [[Category: Mauk, A | + | [[Category: Mauk, A G.]] |
| - | [[Category: Rosell, F | + | [[Category: Rosell, F I.]] |
[[Category: Turano, P.]] | [[Category: Turano, P.]] | ||
[[Category: HEC]] | [[Category: HEC]] | ||
[[Category: alkaline transition; cytochrome c; nmr structure]] | [[Category: alkaline transition; cytochrome c; nmr structure]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:46:23 2008'' |
Revision as of 11:46, 21 February 2008
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Structural model for an alkaline form of ferricytochrome c
Overview
An (15)N-enriched sample of the yeast iso-1-ferricytochrome c triple variant (Lys72Ala/Lys79Ala/Cys102Thr) in an alkaline conformation was examined by NMR spectroscopy. The mutations were planned to produce a cytochrome c with a single conformer. Despite suboptimal conditions for the collection of spectra (i.e., pH approximately equal to 11), NMR remains a suitable investigation technique capable of taking advantage of paramagnetism. 76% of amino acids and 49% of protons were assigned successfully. The assignment was in part achieved through standard methods, in part through the identification of groups maintaining the same conformation as in the native protein at pH 7 and, for a few other residues, through a tentative analysis of internuclear distance predictions. Lys73 was assigned as the axial ligand together with His18. In this manner, 838 meaningful NOEs for 108 amino acids, 50 backbone angle constraints, and 203 pseudocontact shifts permitted the convergence of randomly generated structures to a family of conformers with a backbone RMSD of 1.5 +/- 0.2 A. Most of the native cytochrome c conformation is maintained at high pH. The NOE pattern that involves His18 clearly indicates that the proximal side of the protein, including the 20s and 40s loops, remains essentially intact. Structural differences are concentrated in the 70-80 loop, because of the replacement of Met80 by Lys73 as an axial ligand, and in the 50s helix facing that loop; as a consequence, there is increased exposure of the heme group to solvent. Based on several spectral features, we conclude that the folded polypeptide is highly fluxional.
About this Structure
1LMS is a Single protein structure of sequence from Saccharomyces cerevisiae with as ligand. Full crystallographic information is available from OCA.
Reference
Structural model for an alkaline form of ferricytochrome C., Assfalg M, Bertini I, Dolfi A, Turano P, Mauk AG, Rosell FI, Gray HB, J Am Chem Soc. 2003 Mar 12;125(10):2913-22. PMID:12617658
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