1rci: Difference between revisions

Revision as of 15:49, 21 February 2008

BULLFROG RED CELL L FERRITIN TARTRATE/MG/PH 5.5

OverviewOverview

Ferritin is a highly conserved multisubunit protein in animals, plants and microbes which assembles with cubic symmetry and transports hydrated iron ions and protons to and from a mineralized core in the protein interior. We report here the high resolution structures of recombinant amphibian red-cell L ferritin and two mutants solved under two sets of conditions. In one mutant, Glu56, 57, 58 and 60 were replaced with Ala, producing a lag phase in the kinetics of iron uptake. In the second mutant, His25 was replaced with Tyr with, at most, subtle effects on function. A molecule of betaine, used in the purification, is bound in all structures at the 2-fold axis near the recently identified heme binding site of bacterioferritin and horse spleen L ferritin. Comparisons of the five amphibian structures identify two regions of the molecule in which conformational flexibility may be related to function. The positions and interactions of a set of 10 to 18 side-chains, most of which are on the inner surface of the protein, are sensitive both to solution conditions and to the Glu-->Ala mutation. A subset of these side-chains and a chain of ordered solvent molecules extends from the vicinity of Glu56 to 58 and Glu60 to the 3-fold channel in the wild type protein and may be involved in the transport of either iron or protons. The "spine of hydration" is disrupted in the Glu-->Ala mutant. In contrast, H25Y mutation shifts the positions of backbone atoms between the site of the mutation and the 4-fold axis and side-chain positions throughout the structure; the largest changes in the position of backbone atoms are in the DE loop and E helix, approximately 10 A from the mutation site. In combination, these results indicate that solvation, structural plasticity and cooperative structural changes may play a role in ferritin function. Analogies with the structure and function of ion channel proteins such as annexins are noted.

About this StructureAbout this Structure

1RCI is a Single protein structure of sequence from Rana catesbeiana with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

High resolution crystal structures of amphibian red-cell L ferritin: potential roles for structural plasticity and solvation in function., Trikha J, Theil EC, Allewell NM, J Mol Biol. 1995 May 19;248(5):949-67. PMID:7760335

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-[[Image:1rci.gif|left|200px]]<br /><applet load="1rci" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1rci.gif|left|200px]]<br /><applet load="1rci" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1rci, resolution 2.0&Aring;" />
 '''BULLFROG RED CELL L FERRITIN TARTRATE/MG/PH 5.5'''<br />
 ==Overview==
-Ferritin is a highly conserved multisubunit protein in animals, plants and, microbes which assembles with cubic symmetry and transports hydrated iron, ions and protons to and from a mineralized core in the protein interior., We report here the high resolution structures of recombinant amphibian, red-cell L ferritin and two mutants solved under two sets of conditions., In one mutant, Glu56, 57, 58 and 60 were replaced with Ala, producing a, lag phase in the kinetics of iron uptake. In the second mutant, His25 was, replaced with Tyr with, at most, subtle effects on function. A molecule of, betaine, used in the purification, is bound in all structures at the, 2-fold axis near the recently identified heme binding site of, bacterioferritin and horse spleen L ferritin. Comparisons of the five, amphibian structures identify two regions of the molecule in which, conformational flexibility may be related to function. The positions and, interactions of a set of 10 to 18 side-chains, most of which are on the, inner surface of the protein, are sensitive both to solution conditions, and to the Glu--&gt;Ala mutation. A subset of these side-chains and a chain, of ordered solvent molecules extends from the vicinity of Glu56 to 58 and, Glu60 to the 3-fold channel in the wild type protein and may be involved, in the transport of either iron or protons. The "spine of hydration" is, disrupted in the Glu--&gt;Ala mutant. In contrast, H25Y mutation shifts the, positions of backbone atoms between the site of the mutation and the, 4-fold axis and side-chain positions throughout the structure; the largest, changes in the position of backbone atoms are in the DE loop and E helix, approximately 10 A from the mutation site. In combination, these results, indicate that solvation, structural plasticity and cooperative structural, changes may play a role in ferritin function. Analogies with the structure, and function of ion channel proteins such as annexins are noted.
+Ferritin is a highly conserved multisubunit protein in animals, plants and microbes which assembles with cubic symmetry and transports hydrated iron ions and protons to and from a mineralized core in the protein interior. We report here the high resolution structures of recombinant amphibian red-cell L ferritin and two mutants solved under two sets of conditions. In one mutant, Glu56, 57, 58 and 60 were replaced with Ala, producing a lag phase in the kinetics of iron uptake. In the second mutant, His25 was replaced with Tyr with, at most, subtle effects on function. A molecule of betaine, used in the purification, is bound in all structures at the 2-fold axis near the recently identified heme binding site of bacterioferritin and horse spleen L ferritin. Comparisons of the five amphibian structures identify two regions of the molecule in which conformational flexibility may be related to function. The positions and interactions of a set of 10 to 18 side-chains, most of which are on the inner surface of the protein, are sensitive both to solution conditions and to the Glu--&gt;Ala mutation. A subset of these side-chains and a chain of ordered solvent molecules extends from the vicinity of Glu56 to 58 and Glu60 to the 3-fold channel in the wild type protein and may be involved in the transport of either iron or protons. The "spine of hydration" is disrupted in the Glu--&gt;Ala mutant. In contrast, H25Y mutation shifts the positions of backbone atoms between the site of the mutation and the 4-fold axis and side-chain positions throughout the structure; the largest changes in the position of backbone atoms are in the DE loop and E helix, approximately 10 A from the mutation site. In combination, these results indicate that solvation, structural plasticity and cooperative structural changes may play a role in ferritin function. Analogies with the structure and function of ion channel proteins such as annexins are noted.
 ==About this Structure==
-RCI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rana_catesbeiana Rana catesbeiana] with BET as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1RCI OCA].
+RCI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rana_catesbeiana Rana catesbeiana] with <scene name='pdbligand=BET:'>BET</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RCI OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Rana catesbeiana]]
 [[Category: Single protein]]
-[[Category: Allewell, N.M.]]
+[[Category: Allewell, N M.]]
-[[Category: Theil, E.C.]]
+[[Category: Theil, E C.]]
 [[Category: Trikha, J.]]
 [[Category: BET]]
 [[Category: iron storage]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 01:27:59 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:49:22 2008''