1jpr: Difference between revisions

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[[Image:1jpr.jpg|left|200px]]<br /><applet load="1jpr" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1jpr.jpg|left|200px]]<br /><applet load="1jpr" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1jpr, resolution 1.88Å" />

'''Mn substituted Ribonucleotide reductase R2 from E. coli oxidized by nitric oxide'''<br />

==Overview==

The di-iron carboxylate proteins constitute a diverse class of non-heme, iron enzymes performing a multitude of redox reactions. These reactions, usually involve high-valent Fe-oxo species and are thought to be, controlled by carboxylate shifts. Owing to their short lifetime, the, intermediate structures have so far escaped structural characterization by, X-ray crystallography. In an attempt to map the carboxylate conformations, available to the protein during different redox states and different, ligand environments, we have studied metal-substituted forms of the R2, protein of ribonucleotide reductase from Escherichia coli. In the present, work we have solved the crystal structures of Mn-substituted R2 oxidized, in two different ways. Oxidation was performed using either nitric oxide, or a combination of hydrogen peroxide and hydroxylamine. The two, structures are virtually identical, indicating that the oxidation states, are the same, most likely a mixed-valent MnII-MnIII centre. One of the, carboxylate ligands (D84) adopts a new, so far unseen, conformation, which, could participate in the mechanism for radical generation in R2. E238, adopts a bridging-chelating conformation proposed to be important for, proper O2 activation but not previously observed in the wild-type enzyme., Probable catalase activity was also observed during the oxidation with, H2O2, indicating mechanistic similarities to the di-Mn catalases.

The di-iron carboxylate proteins constitute a diverse class of non-heme iron enzymes performing a multitude of redox reactions. These reactions usually involve high-valent Fe-oxo species and are thought to be controlled by carboxylate shifts. Owing to their short lifetime, the intermediate structures have so far escaped structural characterization by X-ray crystallography. In an attempt to map the carboxylate conformations available to the protein during different redox states and different ligand environments, we have studied metal-substituted forms of the R2 protein of ribonucleotide reductase from Escherichia coli. In the present work we have solved the crystal structures of Mn-substituted R2 oxidized in two different ways. Oxidation was performed using either nitric oxide or a combination of hydrogen peroxide and hydroxylamine. The two structures are virtually identical, indicating that the oxidation states are the same, most likely a mixed-valent MnII-MnIII centre. One of the carboxylate ligands (D84) adopts a new, so far unseen, conformation, which could participate in the mechanism for radical generation in R2. E238 adopts a bridging-chelating conformation proposed to be important for proper O2 activation but not previously observed in the wild-type enzyme. Probable catalase activity was also observed during the oxidation with H2O2, indicating mechanistic similarities to the di-Mn catalases.

==About this Structure==

1JPR 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 MN and HG as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-diphosphate_reductase Ribonucleoside-diphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.1 1.17.4.1] Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1JPR OCA].

1JPR 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=MN:'>MN</scene> and <scene name='pdbligand=HG:'>HG</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-diphosphate_reductase Ribonucleoside-diphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.1 1.17.4.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JPR OCA].

==Reference==

Line 14:

[[Category: Ribonucleoside-diphosphate reductase]]

[[Category: Single protein]]

[[Category: Andersson, M.E.]]

[[Category: Andersson, M E.]]

[[Category: Hogbom, M.]]

[[Category: Nordlund, P.]]

Line 23:

[[Category: radical protein]]

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@@ Line 1: / Line 1: @@
-[[Image:1jpr.jpg|left|200px]]<br /><applet load="1jpr" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1jpr.jpg|left|200px]]<br /><applet load="1jpr" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1jpr, resolution 1.88&Aring;" />
 '''Mn substituted Ribonucleotide reductase R2 from E. coli oxidized by nitric oxide'''<br />
 ==Overview==
-The di-iron carboxylate proteins constitute a diverse class of non-heme, iron enzymes performing a multitude of redox reactions. These reactions, usually involve high-valent Fe-oxo species and are thought to be, controlled by carboxylate shifts. Owing to their short lifetime, the, intermediate structures have so far escaped structural characterization by, X-ray crystallography. In an attempt to map the carboxylate conformations, available to the protein during different redox states and different, ligand environments, we have studied metal-substituted forms of the R2, protein of ribonucleotide reductase from Escherichia coli. In the present, work we have solved the crystal structures of Mn-substituted R2 oxidized, in two different ways. Oxidation was performed using either nitric oxide, or a combination of hydrogen peroxide and hydroxylamine. The two, structures are virtually identical, indicating that the oxidation states, are the same, most likely a mixed-valent MnII-MnIII centre. One of the, carboxylate ligands (D84) adopts a new, so far unseen, conformation, which, could participate in the mechanism for radical generation in R2. E238, adopts a bridging-chelating conformation proposed to be important for, proper O2 activation but not previously observed in the wild-type enzyme., Probable catalase activity was also observed during the oxidation with, H2O2, indicating mechanistic similarities to the di-Mn catalases.
+The di-iron carboxylate proteins constitute a diverse class of non-heme iron enzymes performing a multitude of redox reactions. These reactions usually involve high-valent Fe-oxo species and are thought to be controlled by carboxylate shifts. Owing to their short lifetime, the intermediate structures have so far escaped structural characterization by X-ray crystallography. In an attempt to map the carboxylate conformations available to the protein during different redox states and different ligand environments, we have studied metal-substituted forms of the R2 protein of ribonucleotide reductase from Escherichia coli. In the present work we have solved the crystal structures of Mn-substituted R2 oxidized in two different ways. Oxidation was performed using either nitric oxide or a combination of hydrogen peroxide and hydroxylamine. The two structures are virtually identical, indicating that the oxidation states are the same, most likely a mixed-valent MnII-MnIII centre. One of the carboxylate ligands (D84) adopts a new, so far unseen, conformation, which could participate in the mechanism for radical generation in R2. E238 adopts a bridging-chelating conformation proposed to be important for proper O2 activation but not previously observed in the wild-type enzyme. Probable catalase activity was also observed during the oxidation with H2O2, indicating mechanistic similarities to the di-Mn catalases.
 ==About this Structure==
-JPR 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 MN and HG as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-diphosphate_reductase Ribonucleoside-diphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.1 1.17.4.1] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1JPR OCA].
+JPR 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=MN:'>MN</scene> and <scene name='pdbligand=HG:'>HG</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-diphosphate_reductase Ribonucleoside-diphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.1 1.17.4.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JPR OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Ribonucleoside-diphosphate reductase]]
 [[Category: Single protein]]
-[[Category: Andersson, M.E.]]
+[[Category: Andersson, M E.]]
 [[Category: Hogbom, M.]]
 [[Category: Nordlund, P.]]
@@ Line 23: / Line 23: @@
 [[Category: radical protein]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 18:27:45 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:25:19 2008''