Skip to main content
. Author manuscript; available in PMC: 2012 Jan 28.
Published in final edited form as: J Mol Biol. 2010 Oct 7;405(4):1079–1100. doi: 10.1016/j.jmb.2010.08.058

Figure 10. Structural reasoning behind different ΔZoff preferences between parallel and anti-parallel alignments.

Figure 10

A) and B) illustrate parallel and anti-parallel dimeric coiled coils, respectively (images generated with coiled coils taken from PDB entries 2ZTA and 2NOV, respectively). Cylinders represent local orientation of helices, black spheres show Cα atoms and gray spheres depict Cβ atoms. Only a and d positions are shown. Given the direction of Cα-Cβ vectors on opposite chains, in anti-parallel alignments, a potential steric repulsion between a and a′ residues in adjacent layers (depicted with a dotted line) pushes the preference of ΔZoff away from zero.