1fxi
From Proteopedia
(New page: 200px<br /><applet load="1fxi" size="450" color="white" frame="true" align="right" spinBox="true" caption="1fxi, resolution 2.2Å" /> '''STRUCTURE OF THE [2FE...) |
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| - | [[Image:1fxi.gif|left|200px]]<br /><applet load="1fxi" size=" | + | [[Image:1fxi.gif|left|200px]]<br /><applet load="1fxi" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1fxi, resolution 2.2Å" /> | caption="1fxi, resolution 2.2Å" /> | ||
'''STRUCTURE OF THE [2FE-2S] FERREDOXIN I FROM THE BLUE-GREEN ALGA APHANOTHECE SACRUM AT 2.2 ANGSTROMS RESOLUTION'''<br /> | '''STRUCTURE OF THE [2FE-2S] FERREDOXIN I FROM THE BLUE-GREEN ALGA APHANOTHECE SACRUM AT 2.2 ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Crystals of a [2Fe-2S] ferredoxin (Fd) I with a relative molecular mass of | + | Crystals of a [2Fe-2S] ferredoxin (Fd) I with a relative molecular mass of 10,480 were obtained from the blue-green alga Aphanothece sacrum. Each asymmetric unit of the crystal contains four molecules. An electron density map calculated by the single isomorphous replacement method with the anomalous dispersion at 2.5 A resolution was refined by averaging the four molecules in the asymmetric unit. Positional and isotropic thermal parameters for the non-hydrogen atoms of the four molecules and 158 water molecules were refined to an R-factor (R = sigma[Fo-Fc[/sigma Fo) of 0.23 by the restrained least-squares method. The estimated root-mean-square (r.m.s.) error for the atomic positions is 0.3 A. The r.m.s. deviations of equivalent C alpha atoms of the asymmetric-unit molecules superposed by the least-squares method average 0.35 A. The Fd molecule has a structure like the beta-barrel in the molecule of the [2Fe-2S] Fd from Spirulina platensis. A [2Fe-2S] cluster is bonded covalently to the protein molecule by four Fe-S, in which three of the Fe-S bonds are in a loop segment from position 38 to 47. The hydrophobic core inside the beta-barrel is formed by seven conservative residues: Val15, Val18, Ile24, Leu51, Ile74, Ala79 and Ile87. The molecular surface around Tyr23, Tyr80 and the active center may interact with ferredoxin-NADP+ reductase. One of the two iron atoms of the [2Fe-2S] cluster should be more easily reduced than the other because of differences in the hydrogen-bonding scheme and the hydrophobicity around the atoms. |
==About this Structure== | ==About this Structure== | ||
| - | 1FXI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aphanothece_sacrum Aphanothece sacrum] with FES as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1FXI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aphanothece_sacrum Aphanothece sacrum] with <scene name='pdbligand=FES:'>FES</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FXI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: electron transfer (iron-sulfur protein)]] | [[Category: electron transfer (iron-sulfur protein)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:43:39 2008'' |
Revision as of 10:43, 21 February 2008
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STRUCTURE OF THE [2FE-2S] FERREDOXIN I FROM THE BLUE-GREEN ALGA APHANOTHECE SACRUM AT 2.2 ANGSTROMS RESOLUTION
Overview
Crystals of a [2Fe-2S] ferredoxin (Fd) I with a relative molecular mass of 10,480 were obtained from the blue-green alga Aphanothece sacrum. Each asymmetric unit of the crystal contains four molecules. An electron density map calculated by the single isomorphous replacement method with the anomalous dispersion at 2.5 A resolution was refined by averaging the four molecules in the asymmetric unit. Positional and isotropic thermal parameters for the non-hydrogen atoms of the four molecules and 158 water molecules were refined to an R-factor (R = sigma[Fo-Fc[/sigma Fo) of 0.23 by the restrained least-squares method. The estimated root-mean-square (r.m.s.) error for the atomic positions is 0.3 A. The r.m.s. deviations of equivalent C alpha atoms of the asymmetric-unit molecules superposed by the least-squares method average 0.35 A. The Fd molecule has a structure like the beta-barrel in the molecule of the [2Fe-2S] Fd from Spirulina platensis. A [2Fe-2S] cluster is bonded covalently to the protein molecule by four Fe-S, in which three of the Fe-S bonds are in a loop segment from position 38 to 47. The hydrophobic core inside the beta-barrel is formed by seven conservative residues: Val15, Val18, Ile24, Leu51, Ile74, Ala79 and Ile87. The molecular surface around Tyr23, Tyr80 and the active center may interact with ferredoxin-NADP+ reductase. One of the two iron atoms of the [2Fe-2S] cluster should be more easily reduced than the other because of differences in the hydrogen-bonding scheme and the hydrophobicity around the atoms.
About this Structure
1FXI is a Single protein structure of sequence from Aphanothece sacrum with as ligand. Full crystallographic information is available from OCA.
Reference
Structure of the [2Fe-2S] ferredoxin I from the blue-green alga Aphanothece sacrum at 2.2 A resolution., Tsukihara T, Fukuyama K, Mizushima M, Harioka T, Kusunoki M, Katsube Y, Hase T, Matsubara H, J Mol Biol. 1990 Nov 20;216(2):399-410. PMID:2123937
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