2bs3: Difference between revisions
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[[Image:2bs3.gif|left|200px]]<br /><applet load="2bs3" size=" | [[Image:2bs3.gif|left|200px]]<br /><applet load="2bs3" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2bs3, resolution 2.19Å" /> | caption="2bs3, resolution 2.19Å" /> | ||
'''GLU C180-> GLN VARIANT QUINOL:FUMARATE REDUCTASE FROM WOLINELLA SUCCINOGENES'''<br /> | '''GLU C180-> GLN VARIANT QUINOL:FUMARATE REDUCTASE FROM WOLINELLA SUCCINOGENES'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
2BS3 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 NA, FAD, CIT, FES, F3S, SF4, HEM and LMT 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:// | 2BS3 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]. | ||
==Reference== | ==Reference== | ||
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[[Category: tricarboxylic acid cycle]] | [[Category: tricarboxylic acid cycle]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 10:27:18 2008'' | ||
Revision as of 11:27, 3 February 2008
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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 with , , , , , , and as ligands. Active as Succinate dehydrogenase, with EC number 1.3.99.1 Known structural/functional Site: . 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
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Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)
OCA- Pages with broken file links
- Protein complex
- Succinate dehydrogenase
- Wolinella succinogenes
- Lancaster, C.R.D.
- CIT
- F3S
- FAD
- FES
- HEM
- LMT
- NA
- SF4
- 2fe-2s
- 3d-structure
- 3fe-4s
- 4fe-4s
- Citric acid cycle
- Dihaem cytochrome b
- Electron transport
- Fad
- Flavoprotein
- Fumarate reductase
- Heme
- Ion-sulphur protein
- Iron
- Iron-sulfur
- Metal-binding
- Oxidoreductase
- Respiratory chain
- Transmembrane
- Tricarboxylic acid cycle