1jcc: Difference between revisions

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

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

caption="1jcc, resolution 1.70Å" />

'''Crystal Structure of a Novel Alanine-Zipper Trimer at 1.7 A Resolution, V13A,L16A,V20A,L23A,V27A,M30A,V34A mutations'''<br />

==Overview==

Specific sequence signals at alpha-helix termini can assist protein, folding by punctuating and cueing secondary structural elements in the, final native conformation. Here we report the crystallization of a, 56-residue alanine-containing peptide, denoted Ala-10(56), in the presence, of Zn(2+). The 1.7 A crystal structure shows that Ala-10(56) forms a, parallel trimeric coiled coil with three zinc ions anchoring distinct, capping conformations at the amino-terminal ends of the three helices. In, each polypeptide chain, the free alpha-amino nitrogen and carbonyl oxygen, of the amino-terminal Ser residue coordinate to a Zn(2+) ion to form a, five-membered chelate, and the syn-unidentate interaction of the Asp7 side, chain with the Zn(2+) cation leads to the formation of a unique docking, arrangement for helix capping. Moreover, the coordination of the zinc ion, involves a neighboring trimer molecule in the crystal. Consequently, the, crystal contacts are stabilized by carboxylate-Zn(2+) interactions between, four Ala-10(56) trimers in the crystal lattice. The observed synergy, between the protein-zinc ion recognition and the helix-packing, arrangements would contribute to the conformational specificity of the, Ala-10(56) trimer.

Specific sequence signals at alpha-helix termini can assist protein folding by punctuating and cueing secondary structural elements in the final native conformation. Here we report the crystallization of a 56-residue alanine-containing peptide, denoted Ala-10(56), in the presence of Zn(2+). The 1.7 A crystal structure shows that Ala-10(56) forms a parallel trimeric coiled coil with three zinc ions anchoring distinct capping conformations at the amino-terminal ends of the three helices. In each polypeptide chain, the free alpha-amino nitrogen and carbonyl oxygen of the amino-terminal Ser residue coordinate to a Zn(2+) ion to form a five-membered chelate, and the syn-unidentate interaction of the Asp7 side chain with the Zn(2+) cation leads to the formation of a unique docking arrangement for helix capping. Moreover, the coordination of the zinc ion involves a neighboring trimer molecule in the crystal. Consequently, the crystal contacts are stabilized by carboxylate-Zn(2+) interactions between four Ala-10(56) trimers in the crystal lattice. The observed synergy between the protein-zinc ion recognition and the helix-packing arrangements would contribute to the conformational specificity of the Ala-10(56) trimer.

==About this Structure==

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

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

==Reference==

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[[Category: protein folding]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Tue Nov 20 18~~:06:~~18 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:21:02 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1jcc.gif|left|200px]]<br /><applet load="1jcc" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1jcc.gif|left|200px]]<br /><applet load="1jcc" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1jcc, resolution 1.70&Aring;" />
 '''Crystal Structure of a Novel Alanine-Zipper Trimer at 1.7 A Resolution, V13A,L16A,V20A,L23A,V27A,M30A,V34A mutations'''<br />
 ==Overview==
-Specific sequence signals at alpha-helix termini can assist protein, folding by punctuating and cueing secondary structural elements in the, final native conformation. Here we report the crystallization of a, 56-residue alanine-containing peptide, denoted Ala-10(56), in the presence, of Zn(2+). The 1.7 A crystal structure shows that Ala-10(56) forms a, parallel trimeric coiled coil with three zinc ions anchoring distinct, capping conformations at the amino-terminal ends of the three helices. In, each polypeptide chain, the free alpha-amino nitrogen and carbonyl oxygen, of the amino-terminal Ser residue coordinate to a Zn(2+) ion to form a, five-membered chelate, and the syn-unidentate interaction of the Asp7 side, chain with the Zn(2+) cation leads to the formation of a unique docking, arrangement for helix capping. Moreover, the coordination of the zinc ion, involves a neighboring trimer molecule in the crystal. Consequently, the, crystal contacts are stabilized by carboxylate-Zn(2+) interactions between, four Ala-10(56) trimers in the crystal lattice. The observed synergy, between the protein-zinc ion recognition and the helix-packing, arrangements would contribute to the conformational specificity of the, Ala-10(56) trimer.
+Specific sequence signals at alpha-helix termini can assist protein folding by punctuating and cueing secondary structural elements in the final native conformation. Here we report the crystallization of a 56-residue alanine-containing peptide, denoted Ala-10(56), in the presence of Zn(2+). The 1.7 A crystal structure shows that Ala-10(56) forms a parallel trimeric coiled coil with three zinc ions anchoring distinct capping conformations at the amino-terminal ends of the three helices. In each polypeptide chain, the free alpha-amino nitrogen and carbonyl oxygen of the amino-terminal Ser residue coordinate to a Zn(2+) ion to form a five-membered chelate, and the syn-unidentate interaction of the Asp7 side chain with the Zn(2+) cation leads to the formation of a unique docking arrangement for helix capping. Moreover, the coordination of the zinc ion involves a neighboring trimer molecule in the crystal. Consequently, the crystal contacts are stabilized by carboxylate-Zn(2+) interactions between four Ala-10(56) trimers in the crystal lattice. The observed synergy between the protein-zinc ion recognition and the helix-packing arrangements would contribute to the conformational specificity of the Ala-10(56) trimer.
 ==About this Structure==
-JCC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1JCC OCA].
+JCC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JCC OCA].
 ==Reference==
@@ Line 23: / Line 23: @@
 [[Category: protein folding]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 18:06:18 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:21:02 2008''