1nft: Difference between revisions

Revision as of 15:05, 21 February 2008

OVOTRANSFERRIN, N-TERMINAL LOBE, IRON LOADED OPEN FORM

OverviewOverview

Transferrins bind Fe3+ very tightly in a closed interdomain cleft by the coordination of four protein ligands (Asp60, Tyr92, Tyr191, and His250 in ovotransferrin N-lobe) and of a synergistic anion, physiologically bidentate CO32-. Upon Fe3+ uptake, transferrins undergo a large scale conformational transition: the apo structure with an opening of the interdomain cleft is transformed into the closed holo structure, implying initial Fe3+ binding in the open form. To solve the Fe3+-loaded, domain-opened structure, an ovotransferrin N-lobe crystal that had been grown as the apo form was soaked with Fe3+-nitrilotriacetate, and its structure was solved at 2.1 A resolution. The Fe3+-soaked form showed almost exactly the same overall open structure as the iron-free apo form. The electron density map unequivocally proved the presence of an iron atom with the coordination by the two protein ligands of Tyr92-OH and Tyr191-OH. Other Fe3+ coordination sites are occupied by a nitrilotriacetate anion, which is stabilized through the hydrogen bonds with the peptide NH groups of Ser122, Ala123, and Gly124 and a side chain group of Thr117. There is, however, no clear interaction between the nitrilotriacetate anion and the synergistic anion binding site, Arg121.

About this StructureAbout this Structure

1NFT is a Single protein structure of sequence from Gallus gallus with , and as ligands. Full crystallographic information is available from OCA.

ReferenceReference

Alternative structural state of transferrin. The crystallographic analysis of iron-loaded but domain-opened ovotransferrin N-lobe., Mizutani K, Yamashita H, Kurokawa H, Mikami B, Hirose M, J Biol Chem. 1999 Apr 9;274(15):10190-4. PMID:10187803

Page seeded by OCA on Thu Feb 21 14:05:38 2008

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OCA

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 '''OVOTRANSFERRIN, N-TERMINAL LOBE, IRON LOADED OPEN FORM'''<br />
 ==Overview==
-Transferrins bind Fe3+ very tightly in a closed interdomain cleft by the, coordination of four protein ligands (Asp60, Tyr92, Tyr191, and His250 in, ovotransferrin N-lobe) and of a synergistic anion, physiologically, bidentate CO32-. Upon Fe3+ uptake, transferrins undergo a large scale, conformational transition: the apo structure with an opening of the, interdomain cleft is transformed into the closed holo structure, implying, initial Fe3+ binding in the open form. To solve the Fe3+-loaded, domain-opened structure, an ovotransferrin N-lobe crystal that had been, grown as the apo form was soaked with Fe3+-nitrilotriacetate, and its, structure was solved at 2.1 A resolution. The Fe3+-soaked form showed, almost exactly the same overall open structure as the iron-free apo form., The electron density map unequivocally proved the presence of an iron atom, with the coordination by the two protein ligands of Tyr92-OH and, Tyr191-OH. Other Fe3+ coordination sites are occupied by a, nitrilotriacetate anion, which is stabilized through the hydrogen bonds, with the peptide NH groups of Ser122, Ala123, and Gly124 and a side chain, group of Thr117. There is, however, no clear interaction between the, nitrilotriacetate anion and the synergistic anion binding site, Arg121.
+Transferrins bind Fe3+ very tightly in a closed interdomain cleft by the coordination of four protein ligands (Asp60, Tyr92, Tyr191, and His250 in ovotransferrin N-lobe) and of a synergistic anion, physiologically bidentate CO32-. Upon Fe3+ uptake, transferrins undergo a large scale conformational transition: the apo structure with an opening of the interdomain cleft is transformed into the closed holo structure, implying initial Fe3+ binding in the open form. To solve the Fe3+-loaded, domain-opened structure, an ovotransferrin N-lobe crystal that had been grown as the apo form was soaked with Fe3+-nitrilotriacetate, and its structure was solved at 2.1 A resolution. The Fe3+-soaked form showed almost exactly the same overall open structure as the iron-free apo form. The electron density map unequivocally proved the presence of an iron atom with the coordination by the two protein ligands of Tyr92-OH and Tyr191-OH. Other Fe3+ coordination sites are occupied by a nitrilotriacetate anion, which is stabilized through the hydrogen bonds with the peptide NH groups of Ser122, Ala123, and Gly124 and a side chain group of Thr117. There is, however, no clear interaction between the nitrilotriacetate anion and the synergistic anion binding site, Arg121.
 ==About this Structure==
-NFT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with SO4, FE and NTA as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1NFT OCA].
+NFT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=FE:'>FE</scene> and <scene name='pdbligand=NTA:'>NTA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NFT OCA].
 ==Reference==
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 [[Category: transferrin]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 22:13:18 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:05:38 2008''