2b3x: Difference between revisions

Revision as of 17:33, 21 February 2008

Structure of an orthorhombic crystal form of human cytosolic aconitase (IRP1)

OverviewOverview

Iron regulatory proteins (IRPs) control the translation of proteins involved in iron uptake, storage and utilization by binding to specific noncoding sequences of the corresponding mRNAs known as iron-responsive elements (IREs). This strong interaction assures proper iron homeostasis in animal cells under iron shortage. Conversely, under iron-replete conditions, IRP1 binds a [4Fe-4S] cluster and functions as cytosolic aconitase. Regulation of the balance between the two IRP1 activities is complex, and it does not depend only on iron availability. Here, we report the crystal structure of human IRP1 in its aconitase form. Comparison with known structures of homologous enzymes reveals well-conserved folds and active site environments with significantly different surface shapes and charge distributions. The specific features of human IRP1 allow us to propose a tentative model of an IRP1-IRE complex that agrees with a range of previously obtained data.

About this StructureAbout this Structure

2B3X is a Single protein structure of sequence from Homo sapiens with , and as ligands. Active as Aconitate hydratase, with EC number 4.2.1.3 Full crystallographic information is available from OCA.

ReferenceReference

Crystal structure of human iron regulatory protein 1 as cytosolic aconitase., Dupuy J, Volbeda A, Carpentier P, Darnault C, Moulis JM, Fontecilla-Camps JC, Structure. 2006 Jan;14(1):129-39. PMID:16407072

Page seeded by OCA on Thu Feb 21 16:33:54 2008

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OCA

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-[[Image:2b3x.gif|left|200px]]<br />
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 '''Structure of an orthorhombic crystal form of human cytosolic aconitase (IRP1)'''<br />
 ==Overview==
-Iron regulatory proteins (IRPs) control the translation of proteins, involved in iron uptake, storage and utilization by binding to specific, noncoding sequences of the corresponding mRNAs known as iron-responsive, elements (IREs). This strong interaction assures proper iron homeostasis, in animal cells under iron shortage. Conversely, under iron-replete, conditions, IRP1 binds a [4Fe-4S] cluster and functions as cytosolic, aconitase. Regulation of the balance between the two IRP1 activities is, complex, and it does not depend only on iron availability. Here, we report, the crystal structure of human IRP1 in its aconitase form. Comparison with, known structures of homologous enzymes reveals well-conserved folds and, active site environments with significantly different surface shapes and, charge distributions. The specific features of human IRP1 allow us to, propose a tentative model of an IRP1-IRE complex that agrees with a range, of previously obtained data.
+Iron regulatory proteins (IRPs) control the translation of proteins involved in iron uptake, storage and utilization by binding to specific noncoding sequences of the corresponding mRNAs known as iron-responsive elements (IREs). This strong interaction assures proper iron homeostasis in animal cells under iron shortage. Conversely, under iron-replete conditions, IRP1 binds a [4Fe-4S] cluster and functions as cytosolic aconitase. Regulation of the balance between the two IRP1 activities is complex, and it does not depend only on iron availability. Here, we report the crystal structure of human IRP1 in its aconitase form. Comparison with known structures of homologous enzymes reveals well-conserved folds and active site environments with significantly different surface shapes and charge distributions. The specific features of human IRP1 allow us to propose a tentative model of an IRP1-IRE complex that agrees with a range of previously obtained data.
 ==About this Structure==
-B3X is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with ZN, SF4 and EDO as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aconitate_hydratase Aconitate hydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.3 4.2.1.3] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2B3X OCA].
+B3X is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=SF4:'>SF4</scene> and <scene name='pdbligand=EDO:'>EDO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aconitate_hydratase Aconitate hydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.3 4.2.1.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2B3X OCA].
 ==Reference==
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 [[Category: Single protein]]
 [[Category: Dupuy, J.]]
-[[Category: Fontecilla-Camps, J.C.]]
+[[Category: Fontecilla-Camps, J C.]]
 [[Category: Volbeda, A.]]
 [[Category: EDO]]
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 [[Category: irp1 ire-irp1 aconitase activity]]
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