2min
From Proteopedia
(New page: 200px<br /><applet load="2min" size="450" color="white" frame="true" align="right" spinBox="true" caption="2min, resolution 2.03Å" /> '''NITROGENASE MOFE PRO...) |
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| - | [[Image:2min.gif|left|200px]]<br /><applet load="2min" size=" | + | [[Image:2min.gif|left|200px]]<br /><applet load="2min" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2min, resolution 2.03Å" /> | caption="2min, resolution 2.03Å" /> | ||
'''NITROGENASE MOFE PROTEIN FROM AZOTOBACTER VINELANDII, OXIDIZED STATE'''<br /> | '''NITROGENASE MOFE PROTEIN FROM AZOTOBACTER VINELANDII, OXIDIZED STATE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of the nitrogenase MoFe-protein from Azotobacter vinelandii | + | 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== | ==About this Structure== | ||
| - | 2MIN 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]. This structure | + | 2MIN 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]. This structure supersedes the now removed PDB entry 1MIN. 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=2MIN OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Nitrogenase]] | [[Category: Nitrogenase]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Day, M | + | [[Category: Day, M W.]] |
[[Category: Kim, J.]] | [[Category: Kim, J.]] | ||
| - | [[Category: Peters, J | + | [[Category: Peters, J W.]] |
| - | [[Category: Rees, D | + | [[Category: Rees, D C.]] |
| - | [[Category: Soltis, S | + | [[Category: Soltis, S M.]] |
| - | [[Category: Stowell, M | + | [[Category: Stowell, M H.B.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: CFM]] | [[Category: CFM]] | ||
| Line 30: | Line 30: | ||
[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:07:43 2008'' |
Revision as of 16:07, 21 February 2008
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NITROGENASE MOFE PROTEIN FROM AZOTOBACTER VINELANDII, OXIDIZED STATE
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.
About this Structure
2MIN is a Protein complex structure of sequences from Azotobacter vinelandii with , , and as ligands. This structure supersedes the now removed PDB entry 1MIN. Active as Nitrogenase, with EC number 1.18.6.1 Full crystallographic information is available from OCA.
Reference
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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