1iq7: Difference between revisions
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|PDB= 1iq7 |SIZE=350|CAPTION= <scene name='initialview01'>1iq7</scene>, resolution 2.3Å | |PDB= 1iq7 |SIZE=350|CAPTION= <scene name='initialview01'>1iq7</scene>, resolution 2.3Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene> | |LIGAND= <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> | ||
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY=[[1tfa|1TFA]] | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1iq7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1iq7 OCA], [http://www.ebi.ac.uk/pdbsum/1iq7 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1iq7 RCSB]</span> | |||
}} | }} | ||
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[[Category: Tabata, S.]] | [[Category: Tabata, S.]] | ||
[[Category: Yamashita, H.]] | [[Category: Yamashita, H.]] | ||
[[Category: iron binding protein]] | [[Category: iron binding protein]] | ||
[[Category: ovotransferrin]] | [[Category: ovotransferrin]] | ||
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[[Category: transport protein]] | [[Category: transport protein]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:23:10 2008'' | ||
Revision as of 21:23, 30 March 2008
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| , resolution 2.3Å | |||||||
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| Ligands: | , | ||||||
| Related: | 1TFA
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| 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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