1kbi
From Proteopedia
(New page: 200px<br /><applet load="1kbi" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kbi, resolution 2.3Å" /> '''Crystallographic Stud...) |
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| - | [[Image:1kbi.gif|left|200px]]<br /><applet load="1kbi" size=" | + | [[Image:1kbi.gif|left|200px]]<br /><applet load="1kbi" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1kbi, resolution 2.3Å" /> | caption="1kbi, resolution 2.3Å" /> | ||
'''Crystallographic Study of the Recombinant Flavin-binding Domain of Baker's Yeast Flavocytochrome b2: Comparison with the Intact Wild-type Enzyme'''<br /> | '''Crystallographic Study of the Recombinant Flavin-binding Domain of Baker's Yeast Flavocytochrome b2: Comparison with the Intact Wild-type Enzyme'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Flavocytochrome b(2) catalyzes the oxidation of L-lactate to pyruvate and | + | Flavocytochrome b(2) catalyzes the oxidation of L-lactate to pyruvate and the transfer of electrons to cytochrome c. The enzyme consists of a flavin-binding domain, which includes the active site for lacate oxidation, and a b(2)-cytochrome domain, required for efficient cytochrome c reduction. To better understand the structure and function of intra- and interprotein electron transfer, we have determined the crystal structure of the independently expressed flavin-binding domain of flavocytochrome b(2) to 2.50 A resolution and compared this with the structure of the intact enzyme, redetermined at 2.30 A resolution, both structures being from crystals cooled to 100 K. Whereas there is little overall difference between these structures, we do observe significant local changes near the interface region, some of which impact on amino acid side chains, such as Arg289, that have been shown previously to have an important role in catalysis. The disordered loop region found in flavocytochrome b(2) and its close homologues remain unresolved in frozen crystals of the flavin-binding domain, implying that the presence of the b(2)-cytochrome domain is not responsible for this positional disorder. The flavin-binding domain interacts poorly with cytochrome c, but we have introduced acidic residues in the interdomain interface region with the aim of enhancing cytochrome c binding. While the mutations L199E and K201E within the flavin-binding domain resulted in unimpaired lactate dehydrogenase activity, they failed to enhance electron-transfer rates with cytochrome c. This is most likely due to the disordered loop region obscuring all or part of the surface having the potential for productive interaction with cytochrome c. |
==About this Structure== | ==About this Structure== | ||
| - | 1KBI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with PO4, HEM, FMN, PYR and MPD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/L-lactate_dehydrogenase_(cytochrome) L-lactate dehydrogenase (cytochrome)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.2.3 1.1.2.3] Full crystallographic information is available from [http:// | + | 1KBI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=PO4:'>PO4</scene>, <scene name='pdbligand=HEM:'>HEM</scene>, <scene name='pdbligand=FMN:'>FMN</scene>, <scene name='pdbligand=PYR:'>PYR</scene> and <scene name='pdbligand=MPD:'>MPD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/L-lactate_dehydrogenase_(cytochrome) L-lactate dehydrogenase (cytochrome)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.2.3 1.1.2.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KBI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Saccharomyces cerevisiae]] | [[Category: Saccharomyces cerevisiae]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Barton, J | + | [[Category: Barton, J D.]] |
| - | [[Category: Chapman, S | + | [[Category: Chapman, S K.]] |
| - | [[Category: Chen, Z | + | [[Category: Chen, Z W.]] |
| - | [[Category: Cunane, L | + | [[Category: Cunane, L M.]] |
| - | [[Category: Mathews, F | + | [[Category: Mathews, F S.]] |
| - | [[Category: Reid, G | + | [[Category: Reid, G A.]] |
| - | [[Category: Welsh, F | + | [[Category: Welsh, F E.]] |
[[Category: FMN]] | [[Category: FMN]] | ||
[[Category: HEM]] | [[Category: HEM]] | ||
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[[Category: flavocytochrome b2]] | [[Category: flavocytochrome b2]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:32:12 2008'' |
Revision as of 11:32, 21 February 2008
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Crystallographic Study of the Recombinant Flavin-binding Domain of Baker's Yeast Flavocytochrome b2: Comparison with the Intact Wild-type Enzyme
Overview
Flavocytochrome b(2) catalyzes the oxidation of L-lactate to pyruvate and the transfer of electrons to cytochrome c. The enzyme consists of a flavin-binding domain, which includes the active site for lacate oxidation, and a b(2)-cytochrome domain, required for efficient cytochrome c reduction. To better understand the structure and function of intra- and interprotein electron transfer, we have determined the crystal structure of the independently expressed flavin-binding domain of flavocytochrome b(2) to 2.50 A resolution and compared this with the structure of the intact enzyme, redetermined at 2.30 A resolution, both structures being from crystals cooled to 100 K. Whereas there is little overall difference between these structures, we do observe significant local changes near the interface region, some of which impact on amino acid side chains, such as Arg289, that have been shown previously to have an important role in catalysis. The disordered loop region found in flavocytochrome b(2) and its close homologues remain unresolved in frozen crystals of the flavin-binding domain, implying that the presence of the b(2)-cytochrome domain is not responsible for this positional disorder. The flavin-binding domain interacts poorly with cytochrome c, but we have introduced acidic residues in the interdomain interface region with the aim of enhancing cytochrome c binding. While the mutations L199E and K201E within the flavin-binding domain resulted in unimpaired lactate dehydrogenase activity, they failed to enhance electron-transfer rates with cytochrome c. This is most likely due to the disordered loop region obscuring all or part of the surface having the potential for productive interaction with cytochrome c.
About this Structure
1KBI is a Single protein structure of sequence from Saccharomyces cerevisiae with , , , and as ligands. Active as L-lactate dehydrogenase (cytochrome), with EC number 1.1.2.3 Full crystallographic information is available from OCA.
Reference
Crystallographic study of the recombinant flavin-binding domain of Baker's yeast flavocytochrome b(2): comparison with the intact wild-type enzyme., Cunane LM, Barton JD, Chen ZW, Welsh FE, Chapman SK, Reid GA, Mathews FS, Biochemistry. 2002 Apr 2;41(13):4264-72. PMID:11914072
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