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2bs4
From Proteopedia
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|PDB= 2bs4 |SIZE=350|CAPTION= <scene name='initialview01'>2bs4</scene>, resolution 2.76Å | |PDB= 2bs4 |SIZE=350|CAPTION= <scene name='initialview01'>2bs4</scene>, resolution 2.76Å | ||
|SITE= <scene name='pdbsite=AC1:Dmw+Binding+Site+For+Chain+F'>AC1</scene> | |SITE= <scene name='pdbsite=AC1:Dmw+Binding+Site+For+Chain+F'>AC1</scene> | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=DMW:2,3-DIMETHYL-1,4-NAPHTHOQUINONE'>DMW</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=2bs4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2bs4 OCA], [http://www.ebi.ac.uk/pdbsum/2bs4 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2bs4 RCSB]</span> | ||
}} | }} | ||
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[[Category: Wolinella succinogenes]] | [[Category: Wolinella succinogenes]] | ||
[[Category: Lancaster, C R.D.]] | [[Category: Lancaster, C R.D.]] | ||
| - | [[Category: CIT]] | ||
| - | [[Category: DMW]] | ||
| - | [[Category: F3S]] | ||
| - | [[Category: FAD]] | ||
| - | [[Category: FES]] | ||
| - | [[Category: HEM]] | ||
| - | [[Category: LMT]] | ||
| - | [[Category: NA]] | ||
| - | [[Category: SF4]] | ||
[[Category: 2fe-2]] | [[Category: 2fe-2]] | ||
[[Category: 3fe-4]] | [[Category: 3fe-4]] | ||
| Line 53: | Line 47: | ||
[[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 02:10:56 2008'' |
Revision as of 23:10, 30 March 2008
| |||||||
| , resolution 2.76Å | |||||||
|---|---|---|---|---|---|---|---|
| Sites: | |||||||
| Ligands: | , , , , , , , , | ||||||
| Activity: | Succinate dehydrogenase, with EC number 1.3.99.1 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
GLU C180-> ILE 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
2BS4 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 02:10:56 2008
Categories: Protein complex | Succinate dehydrogenase | Wolinella succinogenes | Lancaster, C R.D. | 2fe-2 | 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
