1ff3
From Proteopedia
(New page: 200px<br /><applet load="1ff3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ff3, resolution 1.9Å" /> '''STRUCTURE OF THE PEPT...) |
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| - | [[Image:1ff3.jpg|left|200px]]<br /><applet load="1ff3" size=" | + | [[Image:1ff3.jpg|left|200px]]<br /><applet load="1ff3" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ff3, resolution 1.9Å" /> | caption="1ff3, resolution 1.9Å" /> | ||
'''STRUCTURE OF THE PEPTIDE METHIONINE SULFOXIDE REDUCTASE FROM ESCHERICHIA COLI'''<br /> | '''STRUCTURE OF THE PEPTIDE METHIONINE SULFOXIDE REDUCTASE FROM ESCHERICHIA COLI'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: Peptide methionine sulphoxide reductases catalyze the | + | BACKGROUND: Peptide methionine sulphoxide reductases catalyze the reduction of oxidized methionine residues in proteins. They are implicated in the defense of organisms against oxidative stress and in the regulation of processes involving peptide methionine oxidation/reduction. These enzymes are found in numerous organisms, from bacteria to mammals and plants. Their primary structure shows no significant similarity to any other known protein. RESULTS: The X-ray structure of the peptide methionine sulphoxide reductase from Escherichia coli was determined at 3 A resolution by the multiple wavelength anomalous dispersion method for the selenomethionine-substituted enzyme, and it was refined to 1.9 A resolution for the native enzyme. The 23 kDa protein is folded into an alpha/beta roll and contains a large proportion of coils. Among the three cysteine residues involved in the catalytic mechanism, Cys-51 is positioned at the N terminus of an alpha helix, in a solvent-exposed area composed of highly conserved amino acids. The two others, Cys-198 and Cys-206, are located in the C-terminal coil. CONCLUSIONS: Sequence alignments show that the overall fold of the peptide methionine sulphoxide reductase from E. coli is likely to be conserved in many species. The characteristics observed in the Cys-51 environment are in agreement with the expected accessibility of the active site of an enzyme that reduces methionine sulphoxides in various proteins. Cys-51 could be activated by the influence of an alpha helix dipole. The involvement of the two other cysteine residues in the catalytic mechanism requires a movement of the C-terminal coil. Several conserved amino acids and water molecules are discussed as potential participants in the reaction. |
==About this Structure== | ==About this Structure== | ||
| - | 1FF3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1FF3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FF3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: pmsr]] | [[Category: pmsr]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:38:06 2008'' |
Revision as of 10:38, 21 February 2008
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STRUCTURE OF THE PEPTIDE METHIONINE SULFOXIDE REDUCTASE FROM ESCHERICHIA COLI
Overview
BACKGROUND: Peptide methionine sulphoxide reductases catalyze the reduction of oxidized methionine residues in proteins. They are implicated in the defense of organisms against oxidative stress and in the regulation of processes involving peptide methionine oxidation/reduction. These enzymes are found in numerous organisms, from bacteria to mammals and plants. Their primary structure shows no significant similarity to any other known protein. RESULTS: The X-ray structure of the peptide methionine sulphoxide reductase from Escherichia coli was determined at 3 A resolution by the multiple wavelength anomalous dispersion method for the selenomethionine-substituted enzyme, and it was refined to 1.9 A resolution for the native enzyme. The 23 kDa protein is folded into an alpha/beta roll and contains a large proportion of coils. Among the three cysteine residues involved in the catalytic mechanism, Cys-51 is positioned at the N terminus of an alpha helix, in a solvent-exposed area composed of highly conserved amino acids. The two others, Cys-198 and Cys-206, are located in the C-terminal coil. CONCLUSIONS: Sequence alignments show that the overall fold of the peptide methionine sulphoxide reductase from E. coli is likely to be conserved in many species. The characteristics observed in the Cys-51 environment are in agreement with the expected accessibility of the active site of an enzyme that reduces methionine sulphoxides in various proteins. Cys-51 could be activated by the influence of an alpha helix dipole. The involvement of the two other cysteine residues in the catalytic mechanism requires a movement of the C-terminal coil. Several conserved amino acids and water molecules are discussed as potential participants in the reaction.
About this Structure
1FF3 is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of the Escherichia coli peptide methionine sulphoxide reductase at 1.9 A resolution., Tete-Favier F, Cobessi D, Boschi-Muller S, Azza S, Branlant G, Aubry A, Structure. 2000 Nov 15;8(11):1167-78. PMID:11080639
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