1kfn
From Proteopedia
(New page: 200px<br /><applet load="1kfn" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kfn, resolution 1.65Å" /> '''Core side-chain pack...) |
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| - | [[Image:1kfn.gif|left|200px]]<br /><applet load="1kfn" size=" | + | [[Image:1kfn.gif|left|200px]]<br /><applet load="1kfn" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1kfn, resolution 1.65Å" /> | caption="1kfn, resolution 1.65Å" /> | ||
'''Core side-chain packing and backbone conformation in Lpp-56 coiled-coil mutants'''<br /> | '''Core side-chain packing and backbone conformation in Lpp-56 coiled-coil mutants'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Native proteins exhibit precise geometric packing of atoms in their | + | 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== | ==About this Structure== | ||
| - | 1KFN 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:// | + | 1KFN 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=1KFN OCA]. |
==Reference== | ==Reference== | ||
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[[Category: protein folding]] | [[Category: protein folding]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:33:36 2008'' |
Revision as of 11:33, 21 February 2008
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Core side-chain packing and backbone conformation in Lpp-56 coiled-coil mutants
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.
About this Structure
1KFN is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Core side-chain packing and backbone conformation in Lpp-56 coiled-coil mutants., Liu J, Cao W, Lu M, J Mol Biol. 2002 May 3;318(3):877-88. PMID:12054830
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