2b76
From Proteopedia
(New page: 200px<br /><applet load="2b76" size="450" color="white" frame="true" align="right" spinBox="true" caption="2b76, resolution 3.300Å" /> '''E. coli Quinol fuma...) |
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| - | [[Image:2b76.gif|left|200px]]<br /><applet load="2b76" size=" | + | [[Image:2b76.gif|left|200px]]<br /><applet load="2b76" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2b76, resolution 3.300Å" /> | caption="2b76, resolution 3.300Å" /> | ||
'''E. coli Quinol fumarate reductase FrdA E49Q mutation'''<br /> | '''E. coli Quinol fumarate reductase FrdA E49Q mutation'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The Escherichia coli complex II homologues succinate:ubiquinone | + | The Escherichia coli complex II homologues succinate:ubiquinone oxidoreductase (SQR, SdhCDAB) and menaquinol:fumarate oxidoreductase (QFR, FrdABCD) have remarkable structural homology at their dicarboxylate binding sites. Although both SQR and QFR can catalyze the interconversion of fumarate and succinate, QFR is a much better fumarate reductase, and SQR is a better succinate oxidase. An exception to the conservation of amino acids near the dicarboxylate binding sites of the two enzymes is that there is a Glu (FrdA Glu-49) near the covalently bound FAD cofactor in most QFRs, which is replaced with a Gln (SdhA Gln-50) in SQRs. The role of the amino acid side chain in enzymes with Glu/Gln/Ala substitutions at FrdA Glu-49 and SdhA Gln-50 has been investigated in this study. The data demonstrate that the mutant enzymes with Ala substitutions in either QFR or SQR remain functionally similar to their wild type counterparts. There were, however, dramatic changes in the catalytic properties when Glu and Gln were exchanged for each other in QFR and SQR. The data show that QFR and SQR enzymes are more efficient succinate oxidases when Gln is in the target position and a better fumarate reductase when Glu is present. Overall, structural and catalytic analyses of the FrdA E49Q and SdhA Q50E mutants suggest that coulombic effects and the electronic state of the FAD are critical in dictating the preferred directionality of the succinate/fumarate interconversions catalyzed by the complex II superfamily. |
==About this Structure== | ==About this Structure== | ||
| - | 2B76 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 FLC, FES, F3S, SF4, FAD and MQ7 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:// | + | 2B76 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=FLC:'>FLC</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> and <scene name='pdbligand=MQ7:'>MQ7</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=2B76 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Succinate dehydrogenase]] | [[Category: Succinate dehydrogenase]] | ||
[[Category: Andrell, J.]] | [[Category: Andrell, J.]] | ||
| - | [[Category: Armstrong, F | + | [[Category: Armstrong, F A.]] |
[[Category: Cecchini, G.]] | [[Category: Cecchini, G.]] | ||
| - | [[Category: Hudson, J | + | [[Category: Hudson, J M.]] |
| - | [[Category: Iverson, T | + | [[Category: Iverson, T M.]] |
[[Category: Kotlyar, V.]] | [[Category: Kotlyar, V.]] | ||
[[Category: Maklashina, E.]] | [[Category: Maklashina, E.]] | ||
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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 16:34:48 2008'' |
Revision as of 14:34, 21 February 2008
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E. coli Quinol fumarate reductase FrdA E49Q mutation
Overview
The Escherichia coli complex II homologues succinate:ubiquinone oxidoreductase (SQR, SdhCDAB) and menaquinol:fumarate oxidoreductase (QFR, FrdABCD) have remarkable structural homology at their dicarboxylate binding sites. Although both SQR and QFR can catalyze the interconversion of fumarate and succinate, QFR is a much better fumarate reductase, and SQR is a better succinate oxidase. An exception to the conservation of amino acids near the dicarboxylate binding sites of the two enzymes is that there is a Glu (FrdA Glu-49) near the covalently bound FAD cofactor in most QFRs, which is replaced with a Gln (SdhA Gln-50) in SQRs. The role of the amino acid side chain in enzymes with Glu/Gln/Ala substitutions at FrdA Glu-49 and SdhA Gln-50 has been investigated in this study. The data demonstrate that the mutant enzymes with Ala substitutions in either QFR or SQR remain functionally similar to their wild type counterparts. There were, however, dramatic changes in the catalytic properties when Glu and Gln were exchanged for each other in QFR and SQR. The data show that QFR and SQR enzymes are more efficient succinate oxidases when Gln is in the target position and a better fumarate reductase when Glu is present. Overall, structural and catalytic analyses of the FrdA E49Q and SdhA Q50E mutants suggest that coulombic effects and the electronic state of the FAD are critical in dictating the preferred directionality of the succinate/fumarate interconversions catalyzed by the complex II superfamily.
About this Structure
2B76 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
Fumarate reductase and succinate oxidase activity of Escherichia coli complex II homologs are perturbed differently by mutation of the flavin binding domain., Maklashina E, Iverson TM, Sher Y, Kotlyar V, Andrell J, Mirza O, Hudson JM, Armstrong FA, Rothery RA, Weiner JH, Cecchini G, J Biol Chem. 2006 Apr 21;281(16):11357-65. Epub 2006 Feb 15. PMID:16484232
Page seeded by OCA on Thu Feb 21 16:34:48 2008
Categories: Escherichia coli | Protein complex | Succinate dehydrogenase | Andrell, J. | Armstrong, F A. | Cecchini, G. | Hudson, J M. | Iverson, T M. | Kotlyar, V. | Maklashina, E. | Mirza, O. | Sher, Y. | F3S | FAD | FES | FLC | MQ7 | SF4 | Electron transfer | Fumarate reductase | Krebs cycle | Membrane protein | Respiration
