1ff2: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1ff2.jpg|left|200px]] | [[Image:1ff2.jpg|left|200px]] | ||
<!-- | |||
The line below this paragraph, containing "STRUCTURE_1ff2", 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_1ff2| PDB=1ff2 | SCENE= }} | |||
}} | |||
'''CRYSTAL STRUCTURE OF THE C42D MUTANT OF AZOTOBACTER VINELANDII 7FE FERREDOXIN (FDI)''' | '''CRYSTAL STRUCTURE OF THE C42D MUTANT OF AZOTOBACTER VINELANDII 7FE FERREDOXIN (FDI)''' | ||
| Line 28: | Line 25: | ||
[[Category: Stout, C D.]] | [[Category: Stout, C D.]] | ||
[[Category: 7fe ferredoxin]] | [[Category: 7fe ferredoxin]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 16:15:00 2008'' | |||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | |||
Revision as of 13:15, 2 May 2008
CRYSTAL STRUCTURE OF THE C42D MUTANT OF AZOTOBACTER VINELANDII 7FE FERREDOXIN (FDI)
Overview
All naturally occurring ferredoxins that have Cys-X-X-Asp-X-X-Cys motifs contain [4Fe-4S](2+/+) clusters that can be easily and reversibly converted to [3Fe-4S](+/0) clusters. In contrast, ferredoxins with unmodified Cys-X-X-Cys-X-X-Cys motifs assemble [4Fe-4S](2+/+) clusters that cannot be easily interconverted with [3Fe-4S](+/0) clusters. In this study we changed the central cysteine of the Cys(39)-X-X-Cys(42)-X-X-Cys(45) of Azotobacter vinelandii FdI, which coordinates its [4Fe-4S](2+/+) cluster, into an aspartate. UV-visible, EPR, and CD spectroscopies, metal analysis, and x-ray crystallography show that, like native FdI, aerobically purified C42D FdI is a seven-iron protein retaining its [4Fe-4S](2+/+) cluster with monodentate aspartate ligation to one iron. Unlike known clusters of this type the reduced [4Fe-4S](+) cluster of C42D FdI exhibits only an S = 1/2 EPR with no higher spin signals detected. The cluster shows only a minor change in reduction potential relative to the native protein. All attempts to convert the cluster to a 3Fe cluster using conventional methods of oxygen or ferricyanide oxidation or thiol exchange were not successful. The cluster conversion was ultimately accomplished using a new electrochemical method. Hydrophobic and electrostatic interaction and the lack of Gly residues adjacent to the Asp ligand explain the remarkable stability of this cluster.
About this Structure
1FF2 is a Single protein structure of sequence from Azotobacter vinelandii. Full crystallographic information is available from OCA.
Reference
Structure of C42D Azotobacter vinelandii FdI. A Cys-X-X-Asp-X-X-Cys motif ligates an air-stable [4Fe-4S]2+/+ cluster., Jung YS, Bonagura CA, Tilley GJ, Gao-Sheridan HS, Armstrong FA, Stout CD, Burgess BK, J Biol Chem. 2000 Nov 24;275(47):36974-83. PMID:10961993 Page seeded by OCA on Fri May 2 16:15:00 2008
