1kfm: Difference between revisions

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

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

caption="1kfm, resolution 2.00Å" />

'''Core side-chain packing and backbone conformation in Lpp-56 coiled-coil mutants'''<br />

==Overview==

Native proteins exhibit precise geometric packing of atoms in their, hydrophobic interiors. Nonetheless, controversy remains about the role of, core side-chain packing in specifying and stabilizing the folded, structures of proteins. Here we investigate the role of core packing in, determining the conformation and stability of the Lpp-56 trimerization, domain. The X-ray crystal structures of Lpp-56 mutants with alanine, substitutions at two and four interior core positions reveal trimeric, coiled coils in which the twist of individual helices and the helix-helix, spacing vary significantly to achieve the most favored superhelical, packing arrangement. Introduction of each alanine "layer" into the, hydrophobic core destabilizes the superhelix by 1.4 kcal mol(-1). Although, the methyl groups of the alanine residues pack at their optimum van der, Waals contacts in the coiled-coil trimer, they provide a smaller component, of hydrophobic interactions than bulky hydrophobic side-chains to the, thermodynamic stability. Thus, specific side-chain packing in the, hydrophobic core of coiled coils are important determinants of protein, main-chain conformation and stability.

Native proteins exhibit precise geometric packing of atoms in their hydrophobic interiors. Nonetheless, controversy remains about the role of core side-chain packing in specifying and stabilizing the folded structures of proteins. Here we investigate the role of core packing in determining the conformation and stability of the Lpp-56 trimerization domain. The X-ray crystal structures of Lpp-56 mutants with alanine substitutions at two and four interior core positions reveal trimeric coiled coils in which the twist of individual helices and the helix-helix spacing vary significantly to achieve the most favored superhelical packing arrangement. Introduction of each alanine "layer" into the hydrophobic core destabilizes the superhelix by 1.4 kcal mol(-1). Although the methyl groups of the alanine residues pack at their optimum van der Waals contacts in the coiled-coil trimer, they provide a smaller component of hydrophobic interactions than bulky hydrophobic side-chains to the thermodynamic stability. Thus, specific side-chain packing in the hydrophobic core of coiled coils are important determinants of protein main-chain conformation and stability.

==About this Structure==

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

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

==Reference==

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[[Category: protein folding]]

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@@ Line 1: / Line 1: @@
-[[Image:1kfm.gif|left|200px]]<br /><applet load="1kfm" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1kfm.gif|left|200px]]<br /><applet load="1kfm" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1kfm, resolution 2.00&Aring;" />
 '''Core side-chain packing and backbone conformation in Lpp-56 coiled-coil mutants'''<br />
 ==Overview==
-Native proteins exhibit precise geometric packing of atoms in their, hydrophobic interiors. Nonetheless, controversy remains about the role of, core side-chain packing in specifying and stabilizing the folded, structures of proteins. Here we investigate the role of core packing in, determining the conformation and stability of the Lpp-56 trimerization, domain. The X-ray crystal structures of Lpp-56 mutants with alanine, substitutions at two and four interior core positions reveal trimeric, coiled coils in which the twist of individual helices and the helix-helix, spacing vary significantly to achieve the most favored superhelical, packing arrangement. Introduction of each alanine "layer" into the, hydrophobic core destabilizes the superhelix by 1.4 kcal mol(-1). Although, the methyl groups of the alanine residues pack at their optimum van der, Waals contacts in the coiled-coil trimer, they provide a smaller component, of hydrophobic interactions than bulky hydrophobic side-chains to the, thermodynamic stability. Thus, specific side-chain packing in the, hydrophobic core of coiled coils are important determinants of protein, main-chain conformation and stability.
+Native proteins exhibit precise geometric packing of atoms in their hydrophobic interiors. Nonetheless, controversy remains about the role of core side-chain packing in specifying and stabilizing the folded structures of proteins. Here we investigate the role of core packing in determining the conformation and stability of the Lpp-56 trimerization domain. The X-ray crystal structures of Lpp-56 mutants with alanine substitutions at two and four interior core positions reveal trimeric coiled coils in which the twist of individual helices and the helix-helix spacing vary significantly to achieve the most favored superhelical packing arrangement. Introduction of each alanine "layer" into the hydrophobic core destabilizes the superhelix by 1.4 kcal mol(-1). Although the methyl groups of the alanine residues pack at their optimum van der Waals contacts in the coiled-coil trimer, they provide a smaller component of hydrophobic interactions than bulky hydrophobic side-chains to the thermodynamic stability. Thus, specific side-chain packing in the hydrophobic core of coiled coils are important determinants of protein main-chain conformation and stability.
 ==About this Structure==
-KFM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1KFM OCA].
+KFM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KFM OCA].
 ==Reference==
@@ Line 22: / Line 22: @@
 [[Category: protein folding]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 19:10:17 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:33:36 2008''