This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1nft
From Proteopedia
(New page: 200px<br /><applet load="1nft" size="450" color="white" frame="true" align="right" spinBox="true" caption="1nft, resolution 2.1Å" /> '''OVOTRANSFERRIN, N-TER...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1nft.gif|left|200px]]<br /><applet load="1nft" size=" | + | [[Image:1nft.gif|left|200px]]<br /><applet load="1nft" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1nft, resolution 2.1Å" /> | caption="1nft, resolution 2.1Å" /> | ||
'''OVOTRANSFERRIN, N-TERMINAL LOBE, IRON LOADED OPEN FORM'''<br /> | '''OVOTRANSFERRIN, N-TERMINAL LOBE, IRON LOADED OPEN FORM'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Transferrins bind Fe3+ very tightly in a closed interdomain cleft by the | + | 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== | ==About this Structure== | ||
| - | 1NFT 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:// | + | 1NFT 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== | ==Reference== | ||
| Line 25: | Line 25: | ||
[[Category: transferrin]] | [[Category: transferrin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:05:38 2008'' |
Revision as of 12:05, 21 February 2008
|
OVOTRANSFERRIN, N-TERMINAL LOBE, IRON LOADED OPEN FORM
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.
About this Structure
1NFT is a Single protein structure of sequence from Gallus gallus with , and as ligands. Full crystallographic information is available from OCA.
Reference
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
Categories: Gallus gallus | Single protein | Hirose, M. | Kurokawa, H. | Mikami, B. | Mizutani, K. | Yamashita, H. | FE | NTA | SO4 | Iron binding protein | Ovotransferrin | Transferrin
