1L4X

Octameric de novo designed peptide

Summary for 1L4X

• Entry DOI: 10.2210/pdb1l4x/pdb
• Related: 1D7M 1HQJ 1KYC
• Descriptor: SIN-ASP-GLU-LEU-GLU-ARG-ALA-ILE-ARG-GLU-LEU-ALA-ALA-ARG-ILE-LYS-NH2, CHLORIDE ION, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: coiled coil, protein de novo design, ionic interactions, protein folding, protein oligomerization, de novo protein
• Biological source: synthetic construct
• Total number of polymer chains: 8
• Total formula weight: 15140.96

Authors

Meier, M.,Lustig, A.,Aebi, U.,Burkhard, P. (deposition date: 2002-03-06, release date: 2002-11-13, Last modification date: 2024-04-24)

Primary citation

Meier, M.,Lustig, A.,Aebi, U.,Burkhard, P.
Removing an interhelical salt bridge abolishes coiled-coil formation in a de novo designed peptide
J.STRUCT.BIOL., 137:65-72, 2002

PubMed Abstract: Alpha-helical coiled coils represent a common protein oligomerization motif that are mainly stabilized by hydrophobic interactions occurring along their coiled-coil interface, the so-called hydrophobic seam. We have recently de novo designed and optimized a series of two-heptad repeat long coiled-coil peptides which are further stabilized by a complex network of inter- and intrahelical salt bridges. Here we have extended the de novo design of such two heptad-repeat long peptides by removing the central and most important g-e' Arg to Glu (g-e'RE) ionic interhelical interaction and replacing these residues by alanine residues. The effect of the missing interhelical ionic interaction on coiled-coil formation and stability has been analyzed by CD spectroscopy, analytical ultracentrifugation, and X-ray crystallography. We show that the peptide, while being highly alpha-helical, is no longer able to form a parallel coiled-coil structure but rather assumes an octameric globular helical assembly devoid of any coiled-coil interactions.

PubMed: 12064934
DOI: 10.1006/jsbi.2002.4467

Experimental method

X-RAY DIFFRACTION (2 Å)