1p9i
From Proteopedia
(New page: 200px<br /><applet load="1p9i" size="450" color="white" frame="true" align="right" spinBox="true" caption="1p9i, resolution 1.17Å" /> '''Coiled-coil X-ray st...) |
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| - | [[Image:1p9i.jpg|left|200px]]<br /><applet load="1p9i" size=" | + | [[Image:1p9i.jpg|left|200px]]<br /><applet load="1p9i" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1p9i, resolution 1.17Å" /> | caption="1p9i, resolution 1.17Å" /> | ||
'''Coiled-coil X-ray structure at 1.17 A resolution'''<br /> | '''Coiled-coil X-ray structure at 1.17 A resolution'''<br /> | ||
==Overview== | ==Overview== | ||
| - | We determined the 1.17 A resolution X-ray crystal structure of a hybrid | + | We determined the 1.17 A resolution X-ray crystal structure of a hybrid peptide based on sequences from coiled-coil regions of the proteins GCN4 and cortexillin I. The peptide forms a parallel homodimeric coiled-coil, with C(alpha) backbone geometry similar to GCN4 (rmsd value 0.71 A). Three stabilizing interactions have been identified: a unique hydrogen bonding-electrostatic network not previously observed in coiled-coils, and two other hydrophobic interactions involving leucine residues at positions e and g from both g-a' and d-e' interchain interactions with the hydrophobic core. This is also the first report of the quantitative significance of these interactions. The GCN4/cortexillin hybrid surprisingly has two interchain Glu-Lys' ion pairs that form a hydrogen bonding network with the Asn residues in the core. This network, which was not observed for the reversed Lys-Glu' pair in GCN4, increases the combined stability contribution of each Glu-Lys' salt bridge across the central Asn15-Asn15' core to approximately 0.7 kcal/mole, compared to approximately 0.4 kcal mole(-1) from a Glu-Lys' salt bridge on its own. In addition to electrostatic and hydrogen bonding stabilization of the coiled-coil, individual leucine residues at positions e and g in the hybrid peptide also contribute to stability by 0.7 kcal/mole relative to alanine. These interactions are of critical importance to understanding the stability requirements for coiled-coil folding and in modulating the stability of de novo designed macromolecules containing this motif. |
==About this Structure== | ==About this Structure== | ||
| - | 1P9I is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http:// | + | 1P9I is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1P9I OCA]. |
==Reference== | ==Reference== | ||
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[[Category: coiled-coil]] | [[Category: coiled-coil]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:26:36 2008'' |
Revision as of 12:26, 21 February 2008
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Coiled-coil X-ray structure at 1.17 A resolution
Overview
We determined the 1.17 A resolution X-ray crystal structure of a hybrid peptide based on sequences from coiled-coil regions of the proteins GCN4 and cortexillin I. The peptide forms a parallel homodimeric coiled-coil, with C(alpha) backbone geometry similar to GCN4 (rmsd value 0.71 A). Three stabilizing interactions have been identified: a unique hydrogen bonding-electrostatic network not previously observed in coiled-coils, and two other hydrophobic interactions involving leucine residues at positions e and g from both g-a' and d-e' interchain interactions with the hydrophobic core. This is also the first report of the quantitative significance of these interactions. The GCN4/cortexillin hybrid surprisingly has two interchain Glu-Lys' ion pairs that form a hydrogen bonding network with the Asn residues in the core. This network, which was not observed for the reversed Lys-Glu' pair in GCN4, increases the combined stability contribution of each Glu-Lys' salt bridge across the central Asn15-Asn15' core to approximately 0.7 kcal/mole, compared to approximately 0.4 kcal mole(-1) from a Glu-Lys' salt bridge on its own. In addition to electrostatic and hydrogen bonding stabilization of the coiled-coil, individual leucine residues at positions e and g in the hybrid peptide also contribute to stability by 0.7 kcal/mole relative to alanine. These interactions are of critical importance to understanding the stability requirements for coiled-coil folding and in modulating the stability of de novo designed macromolecules containing this motif.
About this Structure
1P9I is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Unique stabilizing interactions identified in the two-stranded alpha-helical coiled-coil: crystal structure of a cortexillin I/GCN4 hybrid coiled-coil peptide., Lee DL, Ivaninskii S, Burkhard P, Hodges RS, Protein Sci. 2003 Jul;12(7):1395-405. PMID:12824486
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