1dm5: Difference between revisions

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[[Image:1dm5.gif|left|200px]]<br /><applet load="1dm5" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1dm5.gif|left|200px]]<br /><applet load="1dm5" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1dm5, resolution 1.93Å" />

'''ANNEXIN XII E105K HOMOHEXAMER CRYSTAL STRUCTURE'''<br />

==Overview==

Annexins are a family of calcium- and phospholipid-binding proteins, involved with numerous cellular processes including membrane fusion, ion, channel activity, and heterocomplex formation with other proteins. The, annexin XII (ANXB12) crystal structure presented evidence that calcium, mediates the formation of a hexamer through a novel intermolecular, calcium-binding site [Luecke et al. (1995) Nature 378, 512-515]. In an, attempt to disrupt hexamerization, we mutated a conserved key ligand in, the intermolecular calcium-binding site, Glu105, to lysine. Despite its, occurrence in a new spacegroup, the 1.93 A resolution structure reveals a, hexamer with the Lys105 epsilon-amino group nearly superimposable with the, original intermolecular calcium position. Our analysis shows that the, mutation is directly involved in stabilizing the hexamer. The local, residues are reoriented to retain affinity between the two trimers via a, pH-dependent switch residue, Glu76, which is now protonated, allowing it, to form tandem hydrogen bonds with the backbone carbonyl and nitrogen, atoms of Thr103 located across the trimer interface. The loss of the, intermolecular calcium-binding site is recuperated by extensive hydrogen, bonding favoring hexamer stabilization. The presence of this mutant, structure provides further evidence for hexameric annexin XII, and, possible in vivo roles are discussed.

Annexins are a family of calcium- and phospholipid-binding proteins involved with numerous cellular processes including membrane fusion, ion channel activity, and heterocomplex formation with other proteins. The annexin XII (ANXB12) crystal structure presented evidence that calcium mediates the formation of a hexamer through a novel intermolecular calcium-binding site [Luecke et al. (1995) Nature 378, 512-515]. In an attempt to disrupt hexamerization, we mutated a conserved key ligand in the intermolecular calcium-binding site, Glu105, to lysine. Despite its occurrence in a new spacegroup, the 1.93 A resolution structure reveals a hexamer with the Lys105 epsilon-amino group nearly superimposable with the original intermolecular calcium position. Our analysis shows that the mutation is directly involved in stabilizing the hexamer. The local residues are reoriented to retain affinity between the two trimers via a pH-dependent switch residue, Glu76, which is now protonated, allowing it to form tandem hydrogen bonds with the backbone carbonyl and nitrogen atoms of Thr103 located across the trimer interface. The loss of the intermolecular calcium-binding site is recuperated by extensive hydrogen bonding favoring hexamer stabilization. The presence of this mutant structure provides further evidence for hexameric annexin XII, and possible in vivo roles are discussed.

==About this Structure==

1DM5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hydra_vulgaris Hydra vulgaris] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1DM5 OCA].

1DM5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hydra_vulgaris Hydra vulgaris] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DM5 OCA].

==Reference==

Line 13:

[[Category: Hydra vulgaris]]

[[Category: Single protein]]

[[Category: Cartailler, J.P.]]

[[Category: Cartailler, J P.]]

[[Category: Haigler, H.T.]]

[[Category: Haigler, H T.]]

[[Category: Luecke, H.]]

[[Category: CA]]

Line 23:

[[Category: novel ph-dependent hexamerization switch e76]]

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@@ Line 1: / Line 1: @@
-[[Image:1dm5.gif|left|200px]]<br /><applet load="1dm5" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1dm5.gif|left|200px]]<br /><applet load="1dm5" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1dm5, resolution 1.93&Aring;" />
 '''ANNEXIN XII E105K HOMOHEXAMER CRYSTAL STRUCTURE'''<br />
 ==Overview==
-Annexins are a family of calcium- and phospholipid-binding proteins, involved with numerous cellular processes including membrane fusion, ion, channel activity, and heterocomplex formation with other proteins. The, annexin XII (ANXB12) crystal structure presented evidence that calcium, mediates the formation of a hexamer through a novel intermolecular, calcium-binding site [Luecke et al. (1995) Nature 378, 512-515]. In an, attempt to disrupt hexamerization, we mutated a conserved key ligand in, the intermolecular calcium-binding site, Glu105, to lysine. Despite its, occurrence in a new spacegroup, the 1.93 A resolution structure reveals a, hexamer with the Lys105 epsilon-amino group nearly superimposable with the, original intermolecular calcium position. Our analysis shows that the, mutation is directly involved in stabilizing the hexamer. The local, residues are reoriented to retain affinity between the two trimers via a, pH-dependent switch residue, Glu76, which is now protonated, allowing it, to form tandem hydrogen bonds with the backbone carbonyl and nitrogen, atoms of Thr103 located across the trimer interface. The loss of the, intermolecular calcium-binding site is recuperated by extensive hydrogen, bonding favoring hexamer stabilization. The presence of this mutant, structure provides further evidence for hexameric annexin XII, and, possible in vivo roles are discussed.
+Annexins are a family of calcium- and phospholipid-binding proteins involved with numerous cellular processes including membrane fusion, ion channel activity, and heterocomplex formation with other proteins. The annexin XII (ANXB12) crystal structure presented evidence that calcium mediates the formation of a hexamer through a novel intermolecular calcium-binding site [Luecke et al. (1995) Nature 378, 512-515]. In an attempt to disrupt hexamerization, we mutated a conserved key ligand in the intermolecular calcium-binding site, Glu105, to lysine. Despite its occurrence in a new spacegroup, the 1.93 A resolution structure reveals a hexamer with the Lys105 epsilon-amino group nearly superimposable with the original intermolecular calcium position. Our analysis shows that the mutation is directly involved in stabilizing the hexamer. The local residues are reoriented to retain affinity between the two trimers via a pH-dependent switch residue, Glu76, which is now protonated, allowing it to form tandem hydrogen bonds with the backbone carbonyl and nitrogen atoms of Thr103 located across the trimer interface. The loss of the intermolecular calcium-binding site is recuperated by extensive hydrogen bonding favoring hexamer stabilization. The presence of this mutant structure provides further evidence for hexameric annexin XII, and possible in vivo roles are discussed.
 ==About this Structure==
-DM5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hydra_vulgaris Hydra vulgaris] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1DM5 OCA].
+DM5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hydra_vulgaris Hydra vulgaris] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DM5 OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Hydra vulgaris]]
 [[Category: Single protein]]
-[[Category: Cartailler, J.P.]]
+[[Category: Cartailler, J P.]]
-[[Category: Haigler, H.T.]]
+[[Category: Haigler, H T.]]
 [[Category: Luecke, H.]]
 [[Category: CA]]
@@ Line 23: / Line 23: @@
 [[Category: novel ph-dependent hexamerization switch e76]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 13:23:55 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:18:03 2008''