1siw: Difference between revisions
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[[Image:1siw.gif|left|200px]] | [[Image:1siw.gif|left|200px]] | ||
'''Crystal structure of the apomolybdo-NarGHI''' | {{Structure | ||
|PDB= 1siw |SIZE=350|CAPTION= <scene name='initialview01'>1siw</scene>, resolution 2.20Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=GDP:GUANOSINE-5'-DIPHOSPHATE'>GDP</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=SF4:IRON/SULFUR+CLUSTER'>SF4</scene>, <scene name='pdbligand=F3S:FE3-S4+CLUSTER'>F3S</scene> and <scene name='pdbligand=3PH:1,2-DIACYL-GLYCEROL-3-SN-PHOSPHATE'>3PH</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Nitrate_reductase Nitrate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.7.99.4 1.7.99.4] | |||
|GENE= Operon narGHJI: NARG, NARC, BISD, B1224 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]), Operon narGHJI: NARH, B1225 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]), Operon narGHJI: NARI, CHLI, B1227 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''Crystal structure of the apomolybdo-NarGHI''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1SIW is a [ | 1SIW is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SIW OCA]. | ||
==Reference== | ==Reference== | ||
The catalytic subunit of Escherichia coli nitrate reductase A contains a novel [4Fe-4S] cluster with a high-spin ground state., Rothery RA, Bertero MG, Cammack R, Palak M, Blasco F, Strynadka NC, Weiner JH, Biochemistry. 2004 May 11;43(18):5324-33. PMID:[http:// | The catalytic subunit of Escherichia coli nitrate reductase A contains a novel [4Fe-4S] cluster with a high-spin ground state., Rothery RA, Bertero MG, Cammack R, Palak M, Blasco F, Strynadka NC, Weiner JH, Biochemistry. 2004 May 11;43(18):5324-33. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15122898 15122898] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Nitrate reductase]] | [[Category: Nitrate reductase]] | ||
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[[Category: apomolybdo-narghi; electron-transfer; membrane protein]] | [[Category: apomolybdo-narghi; electron-transfer; membrane protein]] | ||
''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 14:05:29 2008'' | ||
Revision as of 15:05, 20 March 2008
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| , resolution 2.20Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , and | ||||||
| Gene: | Operon narGHJI: NARG, NARC, BISD, B1224 (Escherichia coli), Operon narGHJI: NARH, B1225 (Escherichia coli), Operon narGHJI: NARI, CHLI, B1227 (Escherichia coli) | ||||||
| Activity: | Nitrate reductase, with EC number 1.7.99.4 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of the apomolybdo-NarGHI
OverviewOverview
We have used EPR spectroscopy, redox potentiometry, and protein crystallography to characterize the [4Fe-4S] cluster (FS0) of the Escherichia coli nitrate reductase A (NarGHI) catalytic subunit (NarG). FS0 is clearly visible in the crystal structure of NarGHI [Bertero, M. G., et al. (2003) Nat. Struct. Biol. 10, 681-687] but has novel coordination comprising one His residue and three Cys residues. At low temperatures (<15 K), reduced NarGHI exhibits a previously unobserved EPR signal comprising peaks at g = 5.023 and g = 5.556. We have assigned these features to a [4Fe-4S](+) cluster with an S = (3)/(2) ground state, with the g = 5.023 and g = 5.556 peaks corresponding to subpopulations exhibiting DeltaS = (1)/(2) and DeltaS = (3)/(2) transitions, respectively. Both peaks exhibit midpoint potentials of approximately -55 mV at pH 8.0 and are eliminated in the EPR spectrum of apomolybdo-NarGHI. The structure of apomolybdo-NarGHI reveals that FS0 is still present but that there is significant conformational disorder in a segment of residues that includes one of the Cys ligands. On the basis of these observations, we have assigned the high-spin EPR features of reduced NarGHI to FS0.
About this StructureAbout this Structure
1SIW is a Protein complex structure of sequences from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
The catalytic subunit of Escherichia coli nitrate reductase A contains a novel [4Fe-4S] cluster with a high-spin ground state., Rothery RA, Bertero MG, Cammack R, Palak M, Blasco F, Strynadka NC, Weiner JH, Biochemistry. 2004 May 11;43(18):5324-33. PMID:15122898
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