2bs3: Difference between revisions

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Revision as of 17:06, 20 March 2008

File:2bs3.gif

, resolution 2.19Å

Sites:

Ligands:

, , , , , , and

Activity:

Succinate dehydrogenase, with EC number 1.3.99.1

Coordinates:

save as pdb, mmCIF, xml

GLU C180-> GLN VARIANT QUINOL:FUMARATE REDUCTASE FROM WOLINELLA SUCCINOGENES

OverviewOverview

Reconciliation of apparently contradictory experimental results obtained on the quinol:fumarate reductase, a diheme-containing respiratory membrane protein complex from Wolinella succinogenes, was previously obtained by the proposal of the so-called "E pathway hypothesis." According to this hypothesis, transmembrane electron transfer via the heme groups is strictly coupled to cotransfer of protons via a transiently established pathway thought to contain the side chain of residue Glu-C180 as the most prominent component. Here we demonstrate that, after replacement of Glu-C180 with Gln or Ile by site-directed mutagenesis, the resulting mutants are unable to grow on fumarate, and the membrane-bound variant enzymes lack quinol oxidation activity. Upon solubilization, however, the purified enzymes display approximately 1/10 of the specific quinol oxidation activity of the wild-type enzyme and unchanged quinol Michaelis constants, K(m). The refined x-ray crystal structures at 2.19 A and 2.76 A resolution, respectively, rule out major structural changes to account for these experimental observations. Changes in the oxidation-reduction heme midpoint potential allow the conclusion that deprotonation of Glu-C180 in the wild-type enzyme facilitates the reoxidation of the reduced high-potential heme. Comparison of solvent isotope effects indicates that a rate-limiting proton transfer step in the wild-type enzyme is lost in the Glu-C180 --> Gln variant. The results provide experimental evidence for the validity of the E pathway hypothesis and for a crucial functional role of Glu-C180.

About this StructureAbout this Structure

2BS3 is a Protein complex structure of sequences from Wolinella succinogenes. Full crystallographic information is available from OCA.

ReferenceReference

Experimental support for the "E pathway hypothesis" of coupled transmembrane e- and H+ transfer in dihemic quinol:fumarate reductase., Lancaster CR, Sauer US, Gross R, Haas AH, Graf J, Schwalbe H, Mantele W, Simon J, Madej MG, Proc Natl Acad Sci U S A. 2005 Dec 27;102(52):18860-5. PMID:16380425

Page seeded by OCA on Thu Mar 20 16:06:03 2008

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OCA

@@ Line 1: / Line 1: @@
-[[Image:2bs3.gif|left|200px]]<br /><applet load="2bs3" size="350" color="white" frame="true" align="right" spinBox="true"
+[[Image:2bs3.gif|left|200px]]
-caption="2bs3, resolution 2.19&Aring;" />
-'''GLU C180-> GLN VARIANT QUINOL:FUMARATE REDUCTASE FROM WOLINELLA SUCCINOGENES'''<br />
+ {{Structure
+|PDB= 2bs3 |SIZE=350|CAPTION= <scene name='initialview01'>2bs3</scene>, resolution 2.19&Aring;
+|SITE= <scene name='pdbsite=AC1:Lmt+Binding+Site+For+Chain+F'>AC1</scene>
+|LIGAND= <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=FES:FE2/S2+(INORGANIC)+CLUSTER'>FES</scene>, <scene name='pdbligand=F3S:FE3-S4+CLUSTER'>F3S</scene>, <scene name='pdbligand=SF4:IRON/SULFUR+CLUSTER'>SF4</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene> and <scene name='pdbligand=LMT:DODECYL-BETA-D-MALTOSIDE'>LMT</scene>
+|ACTIVITY= [http://en.wikipedia.org/wiki/Succinate_dehydrogenase Succinate dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.3.99.1 1.3.99.1]
+|GENE=
+}}
+'''GLU C180-> GLN VARIANT QUINOL:FUMARATE REDUCTASE FROM WOLINELLA SUCCINOGENES'''
 ==Overview==
@@ Line 7: / Line 16: @@
 ==About this Structure==
-BS3 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Wolinella_succinogenes Wolinella succinogenes] with <scene name='pdbligand=NA:'>NA</scene>, <scene name='pdbligand=FAD:'>FAD</scene>, <scene name='pdbligand=CIT:'>CIT</scene>, <scene name='pdbligand=FES:'>FES</scene>, <scene name='pdbligand=F3S:'>F3S</scene>, <scene name='pdbligand=SF4:'>SF4</scene>, <scene name='pdbligand=HEM:'>HEM</scene> and <scene name='pdbligand=LMT:'>LMT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Succinate_dehydrogenase Succinate dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.3.99.1 1.3.99.1] Known structural/functional Site: <scene name='pdbsite=AC1:Lmt+Binding+Site+For+Chain+F'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BS3 OCA].
+BS3 is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Wolinella_succinogenes Wolinella succinogenes]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BS3 OCA].
 ==Reference==
-Experimental support for the "E pathway hypothesis" of coupled transmembrane e- and H+ transfer in dihemic quinol:fumarate reductase., Lancaster CR, Sauer US, Gross R, Haas AH, Graf J, Schwalbe H, Mantele W, Simon J, Madej MG, Proc Natl Acad Sci U S A. 2005 Dec 27;102(52):18860-5. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=16380425 16380425]
+Experimental support for the "E pathway hypothesis" of coupled transmembrane e- and H+ transfer in dihemic quinol:fumarate reductase., Lancaster CR, Sauer US, Gross R, Haas AH, Graf J, Schwalbe H, Mantele W, Simon J, Madej MG, Proc Natl Acad Sci U S A. 2005 Dec 27;102(52):18860-5. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16380425 16380425]
 [[Category: Protein complex]]
 [[Category: Succinate dehydrogenase]]
@@ Line 23: / Line 32: @@
 [[Category: NA]]
 [[Category: SF4]]
-[[Category: 2fe-2s]]
+[[Category: 2fe-2]]
 [[Category: 3d-structure]]
-[[Category: 3fe-4s]]
+[[Category: 3fe-4]]
-[[Category: 4fe-4s]]
+[[Category: 4fe-4]]
 [[Category: citric acid cycle]]
 [[Category: dihaem cytochrome b]]
@@ Line 44: / Line 53: @@
 [[Category: tricarboxylic acid cycle]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:41:03 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 16:06:03 2008''