1i55: Difference between revisions

Revision as of 19:35, 2 May 2008

CYTOCHROME C (TUNA) WITH 2ZN:1FE MIXED-METAL PORPHYRINS

OverviewOverview

The current understanding of electron tunneling through proteins has come from work on systems where donors and acceptors are held at fixed distances and orientations. The factors that control electron flow between proteins are less well understood, owing to uncertainties in the relative orientations and structures of the reactants during the very short time that tunneling occurs. As we report here, the way around such structural ambiguity is to examine oxidation-reduction reactions in protein crystals. Accordingly, we have measured and analyzed the kinetics of electron transfer between native and Zn-substituted tuna cytochrome c (cyt c) molecules in crystals of known structure. Electron transfer rates [(320 s(-1) for *Zn-cyt c --> Fe(III)-cyt c; 2000 s(-1) for Fe(II)-cyt c --> Zn-cyt c(+))] over a Zn-Fe distance of 24.1 A closely match those for intraprotein electron tunneling over similar donor-acceptor separations. Our results indicate that van der Waals interactions and water-mediated hydrogen bonds are effective coupling elements for tunneling across a protein-protein interface.

About this StructureAbout this Structure

1I55 is a Single protein structure of sequence from Thunnus thynnus. Full crystallographic information is available from OCA.

ReferenceReference

Electron tunneling in protein crystals., Tezcan FA, Crane BR, Winkler JR, Gray HB, Proc Natl Acad Sci U S A. 2001 Apr 24;98(9):5002-6. Epub 2001 Apr 10. PMID:11296248 Page seeded by OCA on Fri May 2 19:35:10 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
 [[Image:1i55.gif|left|200px]]
- {{Structure
+<!--
-|PDB= 1i55 |SIZE=350|CAPTION= <scene name='initialview01'>1i55</scene>, resolution 2.00&Aring;
+The line below this paragraph, containing "STRUCTURE_1i55", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=ZNH:PROTOPORPHYRIN+IX+CONTAINING+ZN'>ZNH</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY=
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1i55|  PDB=1i55  |  SCENE=  }}
-|RELATEDENTRY=[[3cyt|3CYT]]
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1i55 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1i55 OCA], [http://www.ebi.ac.uk/pdbsum/1i55 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1i55 RCSB]</span>
-}}
 '''CYTOCHROME C (TUNA) WITH 2ZN:1FE MIXED-METAL PORPHYRINS'''
@@ Line 29: / Line 26: @@
 [[Category: Tezcan, F A.]]
 [[Category: Winkler, J R.]]
-[[Category: cytochrome c]]
+[[Category: Cytochrome c]]
-[[Category: electron transfer]]
+[[Category: Electron transfer]]
-[[Category: zinc-porphyrin]]
+[[Category: Zinc-porphyrin]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 19:35:10 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:14:48 2008''