1kfy
From Proteopedia
(New page: 200px<br /><applet load="1kfy" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kfy, resolution 3.6Å" /> '''QUINOL-FUMARATE REDUC...) |
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| - | [[Image:1kfy.jpg|left|200px]]<br /><applet load="1kfy" size=" | + | [[Image:1kfy.jpg|left|200px]]<br /><applet load="1kfy" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1kfy, resolution 3.6Å" /> | caption="1kfy, resolution 3.6Å" /> | ||
'''QUINOL-FUMARATE REDUCTASE WITH QUINOL INHIBITOR 2-[1-(4-CHLORO-PHENYL)-ETHYL]-4,6-DINITRO-PHENOL'''<br /> | '''QUINOL-FUMARATE REDUCTASE WITH QUINOL INHIBITOR 2-[1-(4-CHLORO-PHENYL)-ETHYL]-4,6-DINITRO-PHENOL'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The quinol-fumarate reductase (QFR) respiratory complex of Escherichia | + | The quinol-fumarate reductase (QFR) respiratory complex of Escherichia coli is a four-subunit integral-membrane complex that catalyzes the final step of anaerobic respiration when fumarate is the terminal electron acceptor. The membrane-soluble redox-active molecule menaquinol (MQH(2)) transfers electrons to QFR by binding directly to the membrane-spanning region. The crystal structure of QFR contains two quinone species, presumably MQH(2), bound to the transmembrane-spanning region. The binding sites for the two quinone molecules are termed Q(P) and Q(D), indicating their positions proximal (Q(P)) or distal (Q(D)) to the site of fumarate reduction in the hydrophilic flavoprotein and iron-sulfur protein subunits. It has not been established whether both of these sites are mechanistically significant. Co-crystallization studies of the E. coli QFR with the known quinol-binding site inhibitors 2-heptyl-4-hydroxyquinoline-N-oxide and 2-[1-(p-chlorophenyl)ethyl] 4,6-dinitrophenol establish that both inhibitors block the binding of MQH(2) at the Q(P) site. In the structures with the inhibitor bound at Q(P), no density is observed at Q(D), which suggests that the occupancy of this site can vary and argues against a structurally obligatory role for quinol binding to Q(D). A comparison of the Q(P) site of the E. coli enzyme with quinone-binding sites in other respiratory enzymes shows that an acidic residue is structurally conserved. This acidic residue, Glu-C29, in the E. coli enzyme may act as a proton shuttle from the quinol during enzyme turnover. |
==About this Structure== | ==About this Structure== | ||
| - | 1KFY is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with OAA, FES, F3S, SF4, FAD, BRS and CE1 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] Full crystallographic information is available from [http:// | + | 1KFY is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=OAA:'>OAA</scene>, <scene name='pdbligand=FES:'>FES</scene>, <scene name='pdbligand=F3S:'>F3S</scene>, <scene name='pdbligand=SF4:'>SF4</scene>, <scene name='pdbligand=FAD:'>FAD</scene>, <scene name='pdbligand=BRS:'>BRS</scene> and <scene name='pdbligand=CE1:'>CE1</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] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KFY OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Succinate dehydrogenase]] | [[Category: Succinate dehydrogenase]] | ||
[[Category: Cecchini, G.]] | [[Category: Cecchini, G.]] | ||
| - | [[Category: Croal, L | + | [[Category: Croal, L R.]] |
| - | [[Category: Iverson, T | + | [[Category: Iverson, T M.]] |
[[Category: Luna-Chavez, C.]] | [[Category: Luna-Chavez, C.]] | ||
| - | [[Category: Rees, D | + | [[Category: Rees, D C.]] |
[[Category: BRS]] | [[Category: BRS]] | ||
[[Category: CE1]] | [[Category: CE1]] | ||
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[[Category: succinate dehydrogenase]] | [[Category: succinate dehydrogenase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:33:45 2008'' |
Revision as of 11:33, 21 February 2008
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QUINOL-FUMARATE REDUCTASE WITH QUINOL INHIBITOR 2-[1-(4-CHLORO-PHENYL)-ETHYL]-4,6-DINITRO-PHENOL
Overview
The quinol-fumarate reductase (QFR) respiratory complex of Escherichia coli is a four-subunit integral-membrane complex that catalyzes the final step of anaerobic respiration when fumarate is the terminal electron acceptor. The membrane-soluble redox-active molecule menaquinol (MQH(2)) transfers electrons to QFR by binding directly to the membrane-spanning region. The crystal structure of QFR contains two quinone species, presumably MQH(2), bound to the transmembrane-spanning region. The binding sites for the two quinone molecules are termed Q(P) and Q(D), indicating their positions proximal (Q(P)) or distal (Q(D)) to the site of fumarate reduction in the hydrophilic flavoprotein and iron-sulfur protein subunits. It has not been established whether both of these sites are mechanistically significant. Co-crystallization studies of the E. coli QFR with the known quinol-binding site inhibitors 2-heptyl-4-hydroxyquinoline-N-oxide and 2-[1-(p-chlorophenyl)ethyl] 4,6-dinitrophenol establish that both inhibitors block the binding of MQH(2) at the Q(P) site. In the structures with the inhibitor bound at Q(P), no density is observed at Q(D), which suggests that the occupancy of this site can vary and argues against a structurally obligatory role for quinol binding to Q(D). A comparison of the Q(P) site of the E. coli enzyme with quinone-binding sites in other respiratory enzymes shows that an acidic residue is structurally conserved. This acidic residue, Glu-C29, in the E. coli enzyme may act as a proton shuttle from the quinol during enzyme turnover.
About this Structure
1KFY is a Protein complex structure of sequences from Escherichia coli with , , , , , and as ligands. Active as Succinate dehydrogenase, with EC number 1.3.99.1 Full crystallographic information is available from OCA.
Reference
Crystallographic studies of the Escherichia coli quinol-fumarate reductase with inhibitors bound to the quinol-binding site., Iverson TM, Luna-Chavez C, Croal LR, Cecchini G, Rees DC, J Biol Chem. 2002 May 3;277(18):16124-30. Epub 2002 Feb 15. PMID:11850430
Page seeded by OCA on Thu Feb 21 13:33:45 2008
Categories: Escherichia coli | Protein complex | Succinate dehydrogenase | Cecchini, G. | Croal, L R. | Iverson, T M. | Luna-Chavez, C. | Rees, D C. | BRS | CE1 | F3S | FAD | FES | OAA | SF4 | Fumarate reductase | Membrane protein | Quinol | Quinone | Respiration
