2bs3: Difference between revisions
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|PDB= 2bs3 |SIZE=350|CAPTION= <scene name='initialview01'>2bs3</scene>, resolution 2.19Å | |PDB= 2bs3 |SIZE=350|CAPTION= <scene name='initialview01'>2bs3</scene>, resolution 2.19Å | ||
|SITE= <scene name='pdbsite=AC1:Lmt+Binding+Site+For+Chain+F'>AC1</scene> | |SITE= <scene name='pdbsite=AC1:Lmt+Binding+Site+For+Chain+F'>AC1</scene> | ||
|LIGAND= <scene name='pdbligand= | |LIGAND= <scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=F3S:FE3-S4+CLUSTER'>F3S</scene>, <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=FES:FE2/S2+(INORGANIC)+CLUSTER'>FES</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=LMT:DODECYL-BETA-D-MALTOSIDE'>LMT</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=SF4:IRON/SULFUR+CLUSTER'>SF4</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] | |ACTIVITY= <span class='plainlinks'>[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] </span> | ||
|GENE= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY= | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2bs3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2bs3 OCA], [http://www.ebi.ac.uk/pdbsum/2bs3 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2bs3 RCSB]</span> | |||
}} | }} | ||
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[[Category: Wolinella succinogenes]] | [[Category: Wolinella succinogenes]] | ||
[[Category: Lancaster, C R.D.]] | [[Category: Lancaster, C R.D.]] | ||
[[Category: 2fe-2]] | [[Category: 2fe-2]] | ||
[[Category: 3d-structure]] | [[Category: 3d-structure]] | ||
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[[Category: tricarboxylic acid cycle]] | [[Category: tricarboxylic acid cycle]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 02:10:55 2008'' | ||
Revision as of 23:10, 30 March 2008
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| 2bs3, resolution 2.19Å | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sites: | AC1 | ||||||||||||
| Ligands: | CIT, F3S, FAD, FES, HEM, LMT, NA, SF4 | ||||||||||||
| Activity: | Succinate dehydrogenase, with EC number 1.3.99.1 | ||||||||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
GLU C180-> GLN VARIANT QUINOL:FUMARATE REDUCTASE FROM WOLINELLA SUCCINOGENES
Overview
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 Structure
2BS3 is a Protein complex structure of sequences from Wolinella succinogenes. Full crystallographic information is available from 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:16380425
Page seeded by OCA on Mon Mar 31 02:10:55 2008
Proteopedia Page Contributors and Editors (what is this?)
- Pages with broken file links
- Protein complex
- Succinate dehydrogenase
- Wolinella succinogenes
- Lancaster, C R.D.
- 2fe-2
- 3d-structure
- 3fe-4
- 4fe-4
- 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
