1ce9
From Proteopedia
(New page: 200px<br /><applet load="1ce9" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ce9, resolution 1.8Å" /> '''HELIX CAPPING IN THE ...) |
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| - | [[Image:1ce9.jpg|left|200px]]<br /><applet load="1ce9" size=" | + | [[Image:1ce9.jpg|left|200px]]<br /><applet load="1ce9" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ce9, resolution 1.8Å" /> | caption="1ce9, resolution 1.8Å" /> | ||
'''HELIX CAPPING IN THE GCN4 LEUCINE ZIPPER'''<br /> | '''HELIX CAPPING IN THE GCN4 LEUCINE ZIPPER'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Capping interactions associated with specific sequences at or near the | + | Capping interactions associated with specific sequences at or near the ends of alpha-helices are important determinants of the stability of protein secondary and tertiary structure. We investigate here the role of the helix-capping motif Ser-X-X-Glu, a sequence that occurs frequently at the N termini of alpha helices in proteins, on the conformation and stability of the GCN4 leucine zipper. The 1.8 A resolution crystal structure of the capped molecule reveals distinct conformations, packing geometries and hydrogen-bonding networks at the amino terminus of the two helices in the leucine zipper dimer. The free energy of helix stabilization associated with the hydrogen-bonding and hydrophobic interactions in this capping structure is -1.2 kcal/mol, evaluated from thermal unfolding experiments. A single cap thus contributes appreciably to stabilizing the terminated helix and thereby the native state. These results suggest that helix capping plays a further role in protein folding, providing a sensitive connector linking alpha-helix formation to the developing tertiary structure of a protein. |
==About this Structure== | ==About this Structure== | ||
| - | 1CE9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http:// | + | 1CE9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CE9 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Ji, H.]] | [[Category: Ji, H.]] | ||
| - | [[Category: Kallenbach, N | + | [[Category: Kallenbach, N R.]] |
[[Category: Lu, M.]] | [[Category: Lu, M.]] | ||
[[Category: Shu, W.]] | [[Category: Shu, W.]] | ||
[[Category: Spek, E.]] | [[Category: Spek, E.]] | ||
| - | [[Category: Wang, L | + | [[Category: Wang, L Y.]] |
[[Category: coiled coil]] | [[Category: coiled coil]] | ||
[[Category: helix capping]] | [[Category: helix capping]] | ||
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[[Category: thermal stability]] | [[Category: thermal stability]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:05:22 2008'' |
Revision as of 10:05, 21 February 2008
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HELIX CAPPING IN THE GCN4 LEUCINE ZIPPER
Overview
Capping interactions associated with specific sequences at or near the ends of alpha-helices are important determinants of the stability of protein secondary and tertiary structure. We investigate here the role of the helix-capping motif Ser-X-X-Glu, a sequence that occurs frequently at the N termini of alpha helices in proteins, on the conformation and stability of the GCN4 leucine zipper. The 1.8 A resolution crystal structure of the capped molecule reveals distinct conformations, packing geometries and hydrogen-bonding networks at the amino terminus of the two helices in the leucine zipper dimer. The free energy of helix stabilization associated with the hydrogen-bonding and hydrophobic interactions in this capping structure is -1.2 kcal/mol, evaluated from thermal unfolding experiments. A single cap thus contributes appreciably to stabilizing the terminated helix and thereby the native state. These results suggest that helix capping plays a further role in protein folding, providing a sensitive connector linking alpha-helix formation to the developing tertiary structure of a protein.
About this Structure
1CE9 is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Helix capping in the GCN4 leucine zipper., Lu M, Shu W, Ji H, Spek E, Wang L, Kallenbach NR, J Mol Biol. 1999 May 14;288(4):743-52. PMID:10329176
Page seeded by OCA on Thu Feb 21 12:05:22 2008
