1P9I

Coiled-coil X-ray structure at 1.17 A resolution

1P9I の概要

• エントリーDOI: 10.2210/pdb1p9i/pdb
• 分子名称: cortexillin I/GCN4 hybrid peptide (2 entities in total)
• 機能のキーワード: coiled-coil, unknown function
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 3400.93

構造登録者

Ivaninskii, S. (登録日: 2003-05-12, 公開日: 2003-12-23, 最終更新日: 2024-02-14)

主引用文献

Lee, D.L.,Ivaninskii, S.,Burkhard, P.,Hodges, R.S.
Unique stabilizing interactions identified in the two-stranded alpha-helical coiled-coil: crystal structure of a cortexillin I/GCN4 hybrid coiled-coil peptide.
Protein Sci., 12:1395-1405, 2003

PubMed Abstract: 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.

PubMed: 12824486
DOI: 10.1110/ps.0241403

実験手法

X-RAY DIFFRACTION (1.17 Å)