1m1r: Difference between revisions

Revision as of 00:31, 3 May 2008

Reduced p222 crystal structure of the tetraheme cytochrome c of Shewanella oneidensis MR1

OverviewOverview

The genus Shewanella produces a unique small tetraheme cytochrome c that is implicated in the iron oxide respiration pathway. It is similar in heme content and redox potential to the well known cytochromes c(3) but related in structure to the cytochrome c domain of soluble fumarate reductases from Shewanella sp. We report the crystal structure of the small tetraheme cytochrome c from Shewanella oneidensis MR-1 in two crystal forms and two redox states. The overall fold and heme core are surprisingly different from the soluble fumarate reductase structures. The high resolution obtained for an oxidized orthorhombic crystal (0.97 A) revealed several flexible regions. Comparison of the six monomers in the oxidized monoclinic space group (1.55 A) indicates flexibility in the C-terminal region containing heme IV. The reduced orthorhombic crystal structure (1.02 A) revealed subtle differences in the position of several residues, resulting in decreased solvent accessibility of hemes and the withdrawal of a positive charge from the molecular surface. The packing between monomers indicates that intermolecular electron transfer between any heme pair is possible. This suggests there is no unique site of electron transfer on the surface of the protein and that electron transfer partners may interact with any of the hemes, a process termed "electron-harvesting." This optimizes the efficiency of intermolecular electron transfer by maximizing chances of productive collision with redox partners.

About this StructureAbout this Structure

1M1R is a Single protein structure of sequence from Shewanella oneidensis. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structures at atomic resolution reveal the novel concept of "electron-harvesting" as a role for the small tetraheme cytochrome c., Leys D, Meyer TE, Tsapin AS, Nealson KH, Cusanovich MA, Van Beeumen JJ, J Biol Chem. 2002 Sep 20;277(38):35703-11. Epub 2002 Jun 21. PMID:12080059 Page seeded by OCA on Sat May 3 00:31:53 2008

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OCA

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 '''Reduced p222 crystal structure of the tetraheme cytochrome c of Shewanella oneidensis MR1'''
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 [[Category: Nealson, K H.]]
 [[Category: Tsapin, A I.]]
-[[Category: atomic resolution]]
+[[Category: Atomic resolution]]
-[[Category: reduced structure]]
+[[Category: Reduced structure]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 00:31:53 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:10:10 2008''