1upd: Difference between revisions

Revision as of 16:27, 21 February 2008

OXIDIZED STRUCTURE OF CYTOCHROME C3 FROM DESULFOVIBRIO DESULFURICANS ATCC 27774 AT PH 7.6

OverviewOverview

The tetraheme cytochrome c3 is a small metalloprotein with ca. 13,000 Da found in sulfate-reducing bacteria, which is believed to act as a partner of hydrogenase. The three-dimensional structure of the oxidized and reduced forms of cytochrome c3 from Desulfovibrio desulfuricans ATCC 27774 at pH 7.6 were determined using high-resolution X-ray crystallography and were compared with the previously determined oxidized form at pH 4.0. Theoretical calculations were performed with both structures, using continuum electrostatic calculations and Monte Carlo sampling of protonation and redox states, in order to understand the molecular basis of the redox-Bohr and cooperativity effects related to the coupled transfer of electrons and protons. We were able to identify groups that showed redox-linked conformational changes. In particular, Glu61, His76, and propionate D of heme II showed important contributions to the redox-cooperativity, whereas His76, propionate A of heme I, and propionate D of heme IV were the key residues for the redox-Bohr effect. Upon reduction, an important movement of the backbone region surrounding hemes I and II was also identified, that, together with a few redox-linked conformational changes in side-chain residues, results in a significant decrease in the solvent accessibility of hemes I and II.

About this StructureAbout this Structure

1UPD is a Single protein structure of sequence from Desulfovibrio desulfuricans with as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.

ReferenceReference

Molecular basis for redox-Bohr and cooperative effects in cytochrome c3 from Desulfovibrio desulfuricans ATCC 27774: crystallographic and modeling studies of oxidized and reduced high-resolution structures at pH 7.6., Bento I, Matias PM, Baptista AM, da Costa PN, van Dongen WM, Saraiva LM, Schneider TR, Soares CM, Carrondo MA, Proteins. 2004 Jan 1;54(1):135-52. PMID:14705030

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OCA

@@ Line 4: / Line 4: @@
 ==Overview==
-The tetraheme cytochrome c3 is a small metalloprotein with ca. 13,000 Da, found in sulfate-reducing bacteria, which is believed to act as a partner, of hydrogenase. The three-dimensional structure of the oxidized and, reduced forms of cytochrome c3 from Desulfovibrio desulfuricans ATCC 27774, at pH 7.6 were determined using high-resolution X-ray crystallography and, were compared with the previously determined oxidized form at pH 4.0., Theoretical calculations were performed with both structures, using, continuum electrostatic calculations and Monte Carlo sampling of, protonation and redox states, in order to understand the molecular basis, of the redox-Bohr and cooperativity effects related to the coupled, transfer of electrons and protons. We were able to identify groups that, showed redox-linked conformational changes. In particular, Glu61, His76, and propionate D of heme II showed important contributions to the, redox-cooperativity, whereas His76, propionate A of heme I, and propionate, D of heme IV were the key residues for the redox-Bohr effect. Upon, reduction, an important movement of the backbone region surrounding hemes, I and II was also identified, that, together with a few redox-linked, conformational changes in side-chain residues, results in a significant, decrease in the solvent accessibility of hemes I and II.
+The tetraheme cytochrome c3 is a small metalloprotein with ca. 13,000 Da found in sulfate-reducing bacteria, which is believed to act as a partner of hydrogenase. The three-dimensional structure of the oxidized and reduced forms of cytochrome c3 from Desulfovibrio desulfuricans ATCC 27774 at pH 7.6 were determined using high-resolution X-ray crystallography and were compared with the previously determined oxidized form at pH 4.0. Theoretical calculations were performed with both structures, using continuum electrostatic calculations and Monte Carlo sampling of protonation and redox states, in order to understand the molecular basis of the redox-Bohr and cooperativity effects related to the coupled transfer of electrons and protons. We were able to identify groups that showed redox-linked conformational changes. In particular, Glu61, His76, and propionate D of heme II showed important contributions to the redox-cooperativity, whereas His76, propionate A of heme I, and propionate D of heme IV were the key residues for the redox-Bohr effect. Upon reduction, an important movement of the backbone region surrounding hemes I and II was also identified, that, together with a few redox-linked conformational changes in side-chain residues, results in a significant decrease in the solvent accessibility of hemes I and II.
 ==About this Structure==
@@ Line 13: / Line 13: @@
 [[Category: Desulfovibrio desulfuricans]]
 [[Category: Single protein]]
-[[Category: Baptista, A.M.]]
+[[Category: Baptista, A M.]]
 [[Category: Bento, I.]]
-[[Category: Carrondo, M.A.]]
+[[Category: Carrondo, M A.]]
-[[Category: Costa, P.N.Da.]]
+[[Category: Costa, P N.Da.]]
-[[Category: Dongen, W.M.A.M.Van.]]
+[[Category: Dongen, W M.A M.Van.]]
-[[Category: Matias, P.M.]]
+[[Category: Matias, P M.]]
-[[Category: Saraiva, L.M.]]
+[[Category: Saraiva, L M.]]
-[[Category: Schneider, T.R.]]
+[[Category: Schneider, T R.]]
-[[Category: Soares, C.M.]]
+[[Category: Soares, C M.]]
 [[Category: HEC]]
 [[Category: electron transport]]
 [[Category: tetraheme cytochrome c]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb  3 10:03:39 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:26:59 2008''