1m34: Difference between revisions
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'''Nitrogenase Complex From Azotobacter Vinelandii Stabilized By ADP-Tetrafluoroaluminate''' | {{Structure | ||
|PDB= 1m34 |SIZE=350|CAPTION= <scene name='initialview01'>1m34</scene>, resolution 2.3Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=ALF:TETRAFLUOROALUMINATE+ION'>ALF</scene>, <scene name='pdbligand=HCA:3-HYDROXY-3-CARBOXY-ADIPIC+ACID'>HCA</scene>, <scene name='pdbligand=CFM:FE-MO-S+CLUSTER'>CFM</scene>, <scene name='pdbligand=CLF:FE(8)-S(7)+CLUSTER'>CLF</scene>, <scene name='pdbligand=SF4:IRON/SULFUR+CLUSTER'>SF4</scene> and <scene name='pdbligand=ADP:ADENOSINE-5'-DIPHOSPHATE'>ADP</scene> | |||
|ACTIVITY= [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] | |||
|GENE= | |||
}} | |||
'''Nitrogenase Complex From Azotobacter Vinelandii Stabilized By ADP-Tetrafluoroaluminate''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1M34 is a [ | 1M34 is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M34 OCA]. | ||
==Reference== | ==Reference== | ||
Biochemical and structural characterization of the cross-linked complex of nitrogenase: comparison to the ADP-AlF4(-)-stabilized structure., Schmid B, Einsle O, Chiu HJ, Willing A, Yoshida M, Howard JB, Rees DC, Biochemistry. 2002 Dec 31;41(52):15557-65. PMID:[http:// | Biochemical and structural characterization of the cross-linked complex of nitrogenase: comparison to the ADP-AlF4(-)-stabilized structure., Schmid B, Einsle O, Chiu HJ, Willing A, Yoshida M, Howard JB, Rees DC, Biochemistry. 2002 Dec 31;41(52):15557-65. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12501184 12501184] | ||
[[Category: Azotobacter vinelandii]] | [[Category: Azotobacter vinelandii]] | ||
[[Category: Nitrogenase]] | [[Category: Nitrogenase]] | ||
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[[Category: SF4]] | [[Category: SF4]] | ||
[[Category: atp hydrolysis]] | [[Category: atp hydrolysis]] | ||
[[Category: complex of nitrogenase | [[Category: complex of nitrogenase protein]] | ||
[[Category: electron transfer]] | [[Category: electron transfer]] | ||
[[Category: nitrogen fixation]] | [[Category: nitrogen fixation]] | ||
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[[Category: signal transduction]] | [[Category: signal transduction]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 12:38:17 2008'' | ||
Revision as of 13:38, 20 March 2008
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| , resolution 2.3Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , , , , and | ||||||
| Activity: | Nitrogenase, with EC number 1.18.6.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Nitrogenase Complex From Azotobacter Vinelandii Stabilized By ADP-Tetrafluoroaluminate
OverviewOverview
The transient formation of a complex between the component Fe- and MoFe-proteins of nitrogenase represents a central event in the substrate reduction mechanism of this enzyme. Previously, we have isolated an N-[3-(dimethylamino)propyl]-N'-ethylcarbodiimide (EDC) cross-linked complex of these proteins stabilized by a covalent isopeptide linkage between Glu 112 and Lys beta400 of the Fe-protein and MoFe-protein, respectively [Willing, A., et al. (1989) J. Biol. Chem. 264, 8499-8503; Willing, A., and Howard, J. B. (1990) J. Biol. Chem. 265, 6596-6599]. We report here the biochemical and structural characterization of the cross-linked complex to assess the mechanistic relevance of this species. Glycinamide inhibits the cross-linking reaction, and is found to be specifically incorporated into Glu 112 of the Fe-protein, without detectable modification of either of the neighboring residues (Glu 110 and Glu 111). This modified protein is still competent for substrate reduction, demonstrating that formation of the cross-linked complex is responsible for the enzymatic inactivation, and not the EDC reaction or the modification of the Fe-protein. Crystallographic analysis of the EDC-cross-linked complex at 3.2 A resolution confirms the site of the isopeptide linkage. The nature of the protein surfaces around the cross-linking site suggests there is a strong electrostatic component to the formation of the complex, although the interface area between the component proteins is small. The binding footprints between proteins in the cross-linked complex are adjacent, but with little overlap, to those observed in the complex of the nitrogenase proteins stabilized by ADP-AlF(4)(-). The results of these studies suggest that EDC cross-linking traps a nucleotide-independent precomplex of the nitrogenase proteins driven by complementary electrostatic interactions that subsequently rearranges in a nucleotide-dependent fashion to the electron transfer competent state observed in the ADP-AlF(4)(-) structure.
About this StructureAbout this Structure
1M34 is a Protein complex structure of sequences from Azotobacter vinelandii. Full crystallographic information is available from OCA.
ReferenceReference
Biochemical and structural characterization of the cross-linked complex of nitrogenase: comparison to the ADP-AlF4(-)-stabilized structure., Schmid B, Einsle O, Chiu HJ, Willing A, Yoshida M, Howard JB, Rees DC, Biochemistry. 2002 Dec 31;41(52):15557-65. PMID:12501184
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