2B22

Antiparallel four-stranded coiled coil specified by a 3-3-1 hydrophobic heptad repeat

Summary for 2B22

• Entry DOI: 10.2210/pdb2b22/pdb
• Related: 1GCL 1GCM 2B1F 2ZTA
• Descriptor: General control protein GCN4, SODIUM ION (3 entities in total)
• Functional Keywords: coiled coils, protein design, antiparallel tetramer, ala coils, protein structure, biosynthetic protein
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Cellular location: Nucleus: P03069
• Total number of polymer chains: 1
• Total formula weight: 4032.68

Authors

Deng, Y.,Liu, J.,Zheng, Q.,Eliezer, D.,Kallenbach, N.R.,Lu, M. (deposition date: 2005-09-16, release date: 2006-01-31, Last modification date: 2023-08-23)

Primary citation

Deng, Y.,Liu, J.,Zheng, Q.,Eliezer, D.,Kallenbach, N.R.,Lu, M.
Antiparallel four-stranded coiled coil specified by a 3-3-1 hydrophobic heptad repeat.
Structure, 14:247-255, 2006

PubMed Abstract: Coiled-coil sequences in proteins commonly share a seven-amino acid repeat with nonpolar side chains at the first (a) and fourth (d) positions. We investigate here the role of a 3-3-1 hydrophobic repeat containing nonpolar amino acids at the a, d, and g positions in determining the structures of coiled coils using mutants of the GCN4 leucine zipper dimerization domain. When three charged residues at the g positions in the parental sequence are replaced by nonpolar alanine or valine side chains, stable four-helix structures result. The X-ray crystal structures of the tetramers reveal antiparallel, four-stranded coiled coils in which the a, d, and g side chains interlock in a combination of knobs-into-knobs and knobs-into-holes packing. Interfacial interactions in a coiled coil can therefore be prescribed by hydrophobic-polar patterns beyond the canonical 3-4 heptad repeat. The results suggest that the conserved, charged residues at the g positions in the GCN4 leucine zipper can impart a negative design element to disfavor thermodynamically more stable, antiparallel tetramers.

PubMed: 16472744
DOI: 10.1016/j.str.2005.10.010

Experimental method

X-RAY DIFFRACTION (2 Å)