1ovb: Difference between revisions

Revision as of 15:22, 21 February 2008

THE MECHANISM OF IRON UPTAKE BY TRANSFERRINS: THE STRUCTURE OF AN 18KD NII-DOMAIN FRAGMENT AT 2.3 ANGSTROMS RESOLUTION

OverviewOverview

The molecular structure of an iron-containing 18 kDa fragment of duck ovotransferrin, obtained by proteolysis of the intact protein, has been elucidated by protein crystallographic techniques at 2.3 A resolution. This structure supports a mechanism of iron uptake in the intact protein whereby the binding of the synergistic (bi)carbonate anion is followed by binding of the metal with the lobe in the open configuration. These stages are then followed by domain closure in which the aspartic acid residue plays a further key role, by forming an interdomain hydrogen-bond interaction in addition to serving as a ligand to the iron. This essential dual role is highlighted by model building studies on the C-terminal lobe of a known human variant. In this variant a mutation of a glycine by an arginine residue enables the aspartic acid to form an ion pair and reduce its effectiveness for both metal binding and domain closure. The X-ray structure of the 18 kDa fragment strongly suggests that the histidine residue present at the iron binding site of the intact protein and arising from the second interdomain connecting strand has been removed during the preparative proteolysis.

About this StructureAbout this Structure

1OVB is a Single protein structure of sequence from Anas sp. with and as ligands. Full crystallographic information is available from OCA.

ReferenceReference

The mechanism of iron uptake by transferrins: the structure of an 18 kDa NII-domain fragment from duck ovotransferrin at 2.3 A resolution., Lindley PF, Bajaj M, Evans RW, Garratt RC, Hasnain SS, Jhoti H, Kuser P, Neu M, Patel K, Sarra R, Strange R, Walton A, Acta Crystallogr D Biol Crystallogr. 1993 Mar 1;49(Pt 2):292-304. PMID:15299534

Page seeded by OCA on Thu Feb 21 14:22:08 2008

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OCA

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-[[Image:1ovb.gif|left|200px]]<br /><applet load="1ovb" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1ovb.gif|left|200px]]<br /><applet load="1ovb" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1ovb, resolution 2.3&Aring;" />
 '''THE MECHANISM OF IRON UPTAKE BY TRANSFERRINS: THE STRUCTURE OF AN 18KD NII-DOMAIN FRAGMENT AT 2.3 ANGSTROMS RESOLUTION'''<br />
 ==Overview==
-The molecular structure of an iron-containing 18 kDa fragment of duck, ovotransferrin, obtained by proteolysis of the intact protein, has been, elucidated by protein crystallographic techniques at 2.3 A resolution., This structure supports a mechanism of iron uptake in the intact protein, whereby the binding of the synergistic (bi)carbonate anion is followed by, binding of the metal with the lobe in the open configuration. These stages, are then followed by domain closure in which the aspartic acid residue, plays a further key role, by forming an interdomain hydrogen-bond, interaction in addition to serving as a ligand to the iron. This essential, dual role is highlighted by model building studies on the C-terminal lobe, of a known human variant. In this variant a mutation of a glycine by an, arginine residue enables the aspartic acid to form an ion pair and reduce, its effectiveness for both metal binding and domain closure. The X-ray, structure of the 18 kDa fragment strongly suggests that the histidine, residue present at the iron binding site of the intact protein and arising, from the second interdomain connecting strand has been removed during the, preparative proteolysis.
+The molecular structure of an iron-containing 18 kDa fragment of duck ovotransferrin, obtained by proteolysis of the intact protein, has been elucidated by protein crystallographic techniques at 2.3 A resolution. This structure supports a mechanism of iron uptake in the intact protein whereby the binding of the synergistic (bi)carbonate anion is followed by binding of the metal with the lobe in the open configuration. These stages are then followed by domain closure in which the aspartic acid residue plays a further key role, by forming an interdomain hydrogen-bond interaction in addition to serving as a ligand to the iron. This essential dual role is highlighted by model building studies on the C-terminal lobe of a known human variant. In this variant a mutation of a glycine by an arginine residue enables the aspartic acid to form an ion pair and reduce its effectiveness for both metal binding and domain closure. The X-ray structure of the 18 kDa fragment strongly suggests that the histidine residue present at the iron binding site of the intact protein and arising from the second interdomain connecting strand has been removed during the preparative proteolysis.
 ==About this Structure==
-OVB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Anas_sp. Anas sp.] with FE and CO3 as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1OVB OCA].
+OVB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Anas_sp. Anas sp.] with <scene name='pdbligand=FE:'>FE</scene> and <scene name='pdbligand=CO3:'>CO3</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OVB OCA].
 ==Reference==
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 [[Category: iron transport protein]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 23:13:32 2007''
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