1fo4: Difference between revisions
New page: left|200px<br /><applet load="1fo4" size="450" color="white" frame="true" align="right" spinBox="true" caption="1fo4, resolution 2.1Å" /> '''CRYSTAL STRUCTURE OF ... |
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[[Image:1fo4.gif|left|200px]]<br /><applet load="1fo4" size=" | [[Image:1fo4.gif|left|200px]]<br /><applet load="1fo4" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1fo4, resolution 2.1Å" /> | caption="1fo4, resolution 2.1Å" /> | ||
'''CRYSTAL STRUCTURE OF XANTHINE DEHYDROGENASE ISOLATED FROM BOVINE MILK'''<br /> | '''CRYSTAL STRUCTURE OF XANTHINE DEHYDROGENASE ISOLATED FROM BOVINE MILK'''<br /> | ||
==Overview== | ==Overview== | ||
Mammalian xanthine oxidoreductases, which catalyze the last two steps in | Mammalian xanthine oxidoreductases, which catalyze the last two steps in the formation of urate, are synthesized as the dehydrogenase form xanthine dehydrogenase (XDH) but can be readily converted to the oxidase form xanthine oxidase (XO) by oxidation of sulfhydryl residues or by proteolysis. Here, we present the crystal structure of the dimeric (M(r), 290,000) bovine milk XDH at 2.1-A resolution and XO at 2.5-A resolution and describe the major changes that occur on the proteolytic transformation of XDH to the XO form. Each molecule is composed of an N-terminal 20-kDa domain containing two iron sulfur centers, a central 40-kDa flavin adenine dinucleotide domain, and a C-terminal 85-kDa molybdopterin-binding domain with the four redox centers aligned in an almost linear fashion. Cleavage of surface-exposed loops of XDH causes major structural rearrangement of another loop close to the flavin ring (Gln 423Lys 433). This movement partially blocks access of the NAD substrate to the flavin adenine dinucleotide cofactor and changes the electrostatic environment of the active site, reflecting the switch of substrate specificity observed for the two forms of this enzyme. | ||
==About this Structure== | ==About this Structure== | ||
1FO4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with CA, FES, MTE, MOS, SAL, FAD and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Xanthine_dehydrogenase Xanthine dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.1.4 1.17.1.4] Full crystallographic information is available from [http:// | 1FO4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=FES:'>FES</scene>, <scene name='pdbligand=MTE:'>MTE</scene>, <scene name='pdbligand=MOS:'>MOS</scene>, <scene name='pdbligand=SAL:'>SAL</scene>, <scene name='pdbligand=FAD:'>FAD</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Xanthine_dehydrogenase Xanthine dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.1.4 1.17.1.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FO4 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Xanthine dehydrogenase]] | [[Category: Xanthine dehydrogenase]] | ||
[[Category: Eger, B | [[Category: Eger, B T.]] | ||
[[Category: Enroth, C.]] | [[Category: Enroth, C.]] | ||
[[Category: Nishino, T.]] | [[Category: Nishino, T.]] | ||
[[Category: Okamoto, K.]] | [[Category: Okamoto, K.]] | ||
[[Category: Pai, E | [[Category: Pai, E F.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
[[Category: FAD]] | [[Category: FAD]] | ||
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[[Category: xanthine dehydrogenase]] | [[Category: xanthine dehydrogenase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:40:44 2008'' | ||
Revision as of 13:40, 21 February 2008
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CRYSTAL STRUCTURE OF XANTHINE DEHYDROGENASE ISOLATED FROM BOVINE MILK
OverviewOverview
Mammalian xanthine oxidoreductases, which catalyze the last two steps in the formation of urate, are synthesized as the dehydrogenase form xanthine dehydrogenase (XDH) but can be readily converted to the oxidase form xanthine oxidase (XO) by oxidation of sulfhydryl residues or by proteolysis. Here, we present the crystal structure of the dimeric (M(r), 290,000) bovine milk XDH at 2.1-A resolution and XO at 2.5-A resolution and describe the major changes that occur on the proteolytic transformation of XDH to the XO form. Each molecule is composed of an N-terminal 20-kDa domain containing two iron sulfur centers, a central 40-kDa flavin adenine dinucleotide domain, and a C-terminal 85-kDa molybdopterin-binding domain with the four redox centers aligned in an almost linear fashion. Cleavage of surface-exposed loops of XDH causes major structural rearrangement of another loop close to the flavin ring (Gln 423Lys 433). This movement partially blocks access of the NAD substrate to the flavin adenine dinucleotide cofactor and changes the electrostatic environment of the active site, reflecting the switch of substrate specificity observed for the two forms of this enzyme.
About this StructureAbout this Structure
1FO4 is a Single protein structure of sequence from Bos taurus with , , , , , and as ligands. Active as Xanthine dehydrogenase, with EC number 1.17.1.4 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of bovine milk xanthine dehydrogenase and xanthine oxidase: structure-based mechanism of conversion., Enroth C, Eger BT, Okamoto K, Nishino T, Nishino T, Pai EF, Proc Natl Acad Sci U S A. 2000 Sep 26;97(20):10723-8. PMID:11005854
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