1iq7: Difference between revisions
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'''Ovotransferrin, C-Terminal Lobe, Apo Form''' | {{Structure | ||
|PDB= 1iq7 |SIZE=350|CAPTION= <scene name='initialview01'>1iq7</scene>, resolution 2.3Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene> and <scene name='pdbligand=SO4:SULFATE ION'>SO4</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''Ovotransferrin, C-Terminal Lobe, Apo Form''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1IQ7 is a [ | 1IQ7 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IQ7 OCA]. | ||
==Reference== | ==Reference== | ||
Anion-mediated Fe3+ release mechanism in ovotransferrin C-lobe: a structurally identified SO4(2-) binding site and its implications for the kinetic pathway., Mizutani K, Muralidhara BK, Yamashita H, Tabata S, Mikami B, Hirose M, J Biol Chem. 2001 Sep 21;276(38):35940-6. Epub 2001 Jul 20. PMID:[http:// | Anion-mediated Fe3+ release mechanism in ovotransferrin C-lobe: a structurally identified SO4(2-) binding site and its implications for the kinetic pathway., Mizutani K, Muralidhara BK, Yamashita H, Tabata S, Mikami B, Hirose M, J Biol Chem. 2001 Sep 21;276(38):35940-6. Epub 2001 Jul 20. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11466309 11466309] | ||
[[Category: Gallus gallus]] | [[Category: Gallus gallus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: transport protein]] | [[Category: transport protein]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:53:25 2008'' | ||
Revision as of 12:53, 20 March 2008
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
Ovotransferrin, C-Terminal Lobe, Apo Form
OverviewOverview
The differential properties of anion-mediated Fe(3+) release between the N- and C-lobes of transferrins have been a focus in transferrin biochemistry. The structural and kinetic characteristics for isolated lobe have, however, been documented with the N-lobe only. Here we demonstrate for the first time the quantitative Fe(3+) release kinetics and the anion-binding structure for the isolated C-lobe of ovotransferrin. In the presence of pyrophosphate, sulfate, and nitrilotriacetate anions, the C-lobe released Fe(3+) with a decelerated rate in a single exponential progress curve, and the observed first order rate constants displayed a hyperbolic profile as a function of the anion concentration. The profile was consistent with a newly derived single-pathway Fe(3+) release model in which the holo form is converted depending on the anion concentration into a "mixed ligand" intermediate that releases Fe(3+). The apo C-lobe was crystallized in ammonium sulfate solution, and the structure determined at 2.3 A resolution demonstrated the existence of a single bound SO(4)(2-) in the interdomain cleft, which interacts directly with Thr(461)-OG1, Tyr(431)-OH, and His(592)-NE2 and indirectly with Tyr(524)-OH. The latter three groups are Fe(3+)-coordinating ligands, strongly suggesting the facilitated Fe(3+) release upon the anion occupation at this site. The SO(4)(2-) binding structure supported the single-pathway kinetic model.
About this StructureAbout this Structure
1IQ7 is a Single protein structure of sequence from Gallus gallus. Full crystallographic information is available from OCA.
ReferenceReference
Anion-mediated Fe3+ release mechanism in ovotransferrin C-lobe: a structurally identified SO4(2-) binding site and its implications for the kinetic pathway., Mizutani K, Muralidhara BK, Yamashita H, Tabata S, Mikami B, Hirose M, J Biol Chem. 2001 Sep 21;276(38):35940-6. Epub 2001 Jul 20. PMID:11466309
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