1siw
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1siw.gif|left|200px]] | [[Image:1siw.gif|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1siw", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | + | or leave the SCENE parameter empty for the default display. | |
| - | + | --> | |
| - | + | {{STRUCTURE_1siw| PDB=1siw | SCENE= }} | |
| - | | | + | |
| - | + | ||
| - | }} | + | |
'''Crystal structure of the apomolybdo-NarGHI''' | '''Crystal structure of the apomolybdo-NarGHI''' | ||
| Line 33: | Line 30: | ||
[[Category: Strynadka, N C.]] | [[Category: Strynadka, N C.]] | ||
[[Category: Weiner, J H.]] | [[Category: Weiner, J H.]] | ||
| - | [[Category: | + | [[Category: Apomolybdo-narghi]] |
| - | [[Category: | + | [[Category: Electron-transfer]] |
| - | [[Category: | + | [[Category: Membrane protein]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 08:45:20 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 05:45, 3 May 2008
Crystal structure of the apomolybdo-NarGHI
Overview
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 Structure
1SIW is a Protein complex structure of sequences from Escherichia coli. Full crystallographic information is available from OCA.
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:15122898 Page seeded by OCA on Sat May 3 08:45:20 2008
