3min: Difference between revisions

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NITROGENASE MOFE PROTEIN FROM AZOTOBACTER VINELANDII, OXIDIZED STATE

OverviewOverview

The structure of the nitrogenase MoFe-protein from Azotobacter vinelandii has been refined to 2.0 A resolution in two oxidation states. EPR studies on the crystals indicate that the structures correspond to the spectroscopically assigned oxidized (P(OX)/M(OX)) and the native or dithionite-reduced (P(N)/M(N)) forms of the enzyme. Both MoFe-protein structures are essentially identical, with the exception of the P-cluster. The MoFe-protein P-cluster in each state is found to contain eight Fe and seven S atoms. Interconversion between the two redox states involves movement of two Fe atoms and an exchange of protein coordination for ligands supplied by a central S atom. In the oxidized P(OX) state, the cluster is coordinated by the protein through six cysteine ligands, Ser-beta188 O gamma, and the backbone amide of Cys-alpha88. In the native P(N) state, Ser-beta188 O gamma and the amide N of Cys-alpha88 no longer coordinate the cluster due to movement of their coordinated Fe atoms toward the central sulfur. Consequently, this central sulfur adopts a distorted octahedral environment with six surrounding Fe atoms. A previously described model of the P-cluster containing 8Fe-8S likely reflects the inappropriate modeling of a single structure to a mixture of these two P-cluster redox states. These observed redox-mediated structural changes of the P-cluster suggest a role for this cluster in coupling electron transfer and proton transfer in nitrogenase.

About this StructureAbout this Structure

3MIN is a Protein complex structure of sequences from Azotobacter vinelandii with , , and as ligands. Active as Nitrogenase, with EC number 1.18.6.1 Full crystallographic information is available from OCA.

ReferenceReference

Redox-dependent structural changes in the nitrogenase P-cluster., Peters JW, Stowell MH, Soltis SM, Finnegan MG, Johnson MK, Rees DC, Biochemistry. 1997 Feb 11;36(6):1181-7. PMID:9063865

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-[[Image:3min.gif|left|200px]]<br /><applet load="3min" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:3min.gif|left|200px]]<br /><applet load="3min" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="3min, resolution 2.03&Aring;" />
 '''NITROGENASE MOFE PROTEIN FROM AZOTOBACTER VINELANDII, OXIDIZED STATE'''<br />
 ==Overview==
-The structure of the nitrogenase MoFe-protein from Azotobacter vinelandii, has been refined to 2.0 A resolution in two oxidation states. EPR studies, on the crystals indicate that the structures correspond to the, spectroscopically assigned oxidized (P(OX)/M(OX)) and the native or, dithionite-reduced (P(N)/M(N)) forms of the enzyme. Both MoFe-protein, structures are essentially identical, with the exception of the P-cluster., The MoFe-protein P-cluster in each state is found to contain eight Fe and, seven S atoms. Interconversion between the two redox states involves, movement of two Fe atoms and an exchange of protein coordination for, ligands supplied by a central S atom. In the oxidized P(OX) state, the, cluster is coordinated by the protein through six cysteine ligands, Ser-beta188 O gamma, and the backbone amide of Cys-alpha88. In the native, P(N) state, Ser-beta188 O gamma and the amide N of Cys-alpha88 no longer, coordinate the cluster due to movement of their coordinated Fe atoms, toward the central sulfur. Consequently, this central sulfur adopts a, distorted octahedral environment with six surrounding Fe atoms. A, previously described model of the P-cluster containing 8Fe-8S likely, reflects the inappropriate modeling of a single structure to a mixture of, these two P-cluster redox states. These observed redox-mediated structural, changes of the P-cluster suggest a role for this cluster in coupling, electron transfer and proton transfer in nitrogenase.
+The structure of the nitrogenase MoFe-protein from Azotobacter vinelandii has been refined to 2.0 A resolution in two oxidation states. EPR studies on the crystals indicate that the structures correspond to the spectroscopically assigned oxidized (P(OX)/M(OX)) and the native or dithionite-reduced (P(N)/M(N)) forms of the enzyme. Both MoFe-protein structures are essentially identical, with the exception of the P-cluster. The MoFe-protein P-cluster in each state is found to contain eight Fe and seven S atoms. Interconversion between the two redox states involves movement of two Fe atoms and an exchange of protein coordination for ligands supplied by a central S atom. In the oxidized P(OX) state, the cluster is coordinated by the protein through six cysteine ligands, Ser-beta188 O gamma, and the backbone amide of Cys-alpha88. In the native P(N) state, Ser-beta188 O gamma and the amide N of Cys-alpha88 no longer coordinate the cluster due to movement of their coordinated Fe atoms toward the central sulfur. Consequently, this central sulfur adopts a distorted octahedral environment with six surrounding Fe atoms. A previously described model of the P-cluster containing 8Fe-8S likely reflects the inappropriate modeling of a single structure to a mixture of these two P-cluster redox states. These observed redox-mediated structural changes of the P-cluster suggest a role for this cluster in coupling electron transfer and proton transfer in nitrogenase.
 ==About this Structure==
-MIN is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii] with CA, HCA, CLF and CFM as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Nitrogenase Nitrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.18.6.1 1.18.6.1] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=3MIN OCA].
+MIN is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=HCA:'>HCA</scene>, <scene name='pdbligand=CLF:'>CLF</scene> and <scene name='pdbligand=CFM:'>CFM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Nitrogenase Nitrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.18.6.1 1.18.6.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3MIN OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Nitrogenase]]
 [[Category: Protein complex]]
-[[Category: Day, M.W.]]
+[[Category: Day, M W.]]
 [[Category: Kim, J.]]
-[[Category: Peters, J.W.]]
+[[Category: Peters, J W.]]
-[[Category: Rees, D.C.]]
+[[Category: Rees, D C.]]
-[[Category: Soltis, S.M.]]
+[[Category: Soltis, S M.]]
-[[Category: Stowell, M.H.B.]]
+[[Category: Stowell, M H.B.]]
 [[Category: CA]]
 [[Category: CFM]]
@@ Line 30: / Line 30: @@
 [[Category: oxidoreductase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 19:52:26 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:10:20 2008''