1fo4: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1fo4.gif|left|200px]] | [[Image:1fo4.gif|left|200px]] | ||
<!-- | |||
The line below this paragraph, containing "STRUCTURE_1fo4", creates the "Structure Box" on the page. | |||
You may change the PDB parameter (which sets the PDB file loaded into the applet) | |||
or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |||
or leave the SCENE parameter empty for the default display. | |||
| | --> | ||
| | {{STRUCTURE_1fo4| PDB=1fo4 | SCENE= }} | ||
}} | |||
'''CRYSTAL STRUCTURE OF XANTHINE DEHYDROGENASE ISOLATED FROM BOVINE MILK''' | '''CRYSTAL STRUCTURE OF XANTHINE DEHYDROGENASE ISOLATED FROM BOVINE MILK''' | ||
| Line 32: | Line 29: | ||
[[Category: Pai, E F.]] | [[Category: Pai, E F.]] | ||
[[Category: 2fe-2s iron sulfur center]] | [[Category: 2fe-2s iron sulfur center]] | ||
[[Category: | [[Category: Fad]] | ||
[[Category: | [[Category: Molybdopterin]] | ||
[[Category: | [[Category: Salicylate]] | ||
[[Category: | [[Category: Xanthine dehydrogenase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 16:33:42 2008'' | |||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | |||
Revision as of 16:33, 2 May 2008
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. 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 Page seeded by OCA on Fri May 2 16:33:42 2008