2HY6

A seven-helix coiled coil

Summary for 2HY6

• Entry DOI: 10.2210/pdb2hy6/pdb
• Related: 1GCL 1GCM 2B1F 2B22 2ZTA
• Descriptor: General control protein GCN4, HEXANE-1,6-DIOL (3 entities in total)
• Functional Keywords: protein design, parallel heptamer, protein structure, biosynthetic protein
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Cellular location: Nucleus: P03069
• Total number of polymer chains: 7
• Total formula weight: 26454.84

Authors

Liu, J.,Zheng, Q.,Deng, Y.,Cheng, C.S.,Kallenbach, N.R.,Lu, M. (deposition date: 2006-08-04, release date: 2006-10-24, Last modification date: 2023-08-30)

Primary citation

Liu, J.,Zheng, Q.,Deng, Y.,Cheng, C.S.,Kallenbach, N.R.,Lu, M.
A seven-helix coiled coil.
Proc.Natl.Acad.Sci.Usa, 103:15457-15462, 2006

PubMed Abstract: Coiled-coil proteins contain a characteristic seven-residue sequence repeat whose positions are designated a to g. The interacting surface between alpha-helices in a classical coiled coil is formed by interspersing nonpolar side chains at the a and d positions with hydrophilic residues at the flanking e and g positions. To explore how the chemical nature of these core amino acids dictates the overall coiled-coil architecture, we replaced all eight e and g residues in the GCN4 leucine zipper with nonpolar alanine side chains. Surprisingly, the alanine-containing mutant forms a stable alpha-helical heptamer in aqueous solution. The 1.25-A resolution crystal structure of the heptamer reveals a parallel seven-stranded coiled coil enclosing a large tubular channel with an unusual heptad register shift between adjacent staggered helices. The overall geometry comprises two interleaved hydrophobic helical screws of interacting cross-sectional a and d layers that have not been seen before. Moreover, asparagines at the a positions play an essential role in heptamer formation by participating in a set of buried interhelix hydrogen bonds. These results demonstrate that heptad repeats containing four hydrophobic positions can direct assembly of complex, higher-order coiled-coil structures with rich diversity for close packing of alpha-helices.

PubMed: 17030805
DOI: 10.1073/pnas.0604871103

Experimental method

X-RAY DIFFRACTION (1.25 Å)