1CE9

HELIX CAPPING IN THE GCN4 LEUCINE ZIPPER

1CE9 の概要

• エントリーDOI: 10.2210/pdb1ce9/pdb
• 分子名称: PROTEIN (GCN4-PMSE) (2 entities in total)
• 機能のキーワード: helix capping, leucine zipper, hydrogen bonding, thermal stability, protein folding
• 細胞内の位置: Nucleus: P03069
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 16142.65

構造登録者

Lu, M.,Shu, W.,Ji, H.,Spek, E.,Wang, L.-Y.,Kallenbach, N.R. (登録日: 1999-03-18, 公開日: 1999-03-25, 最終更新日: 2023-08-09)

主引用文献

Lu, M.,Shu, W.,Ji, H.,Spek, E.,Wang, L.,Kallenbach, N.R.
Helix capping in the GCN4 leucine zipper.
J.Mol.Biol., 288:743-752, 1999

PubMed Abstract: 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.

PubMed: 10329176
DOI: 10.1006/jmbi.1999.2707

実験手法

X-RAY DIFFRACTION (1.8 Å)