Figure 1.

Structural features of coiled-coils built up by Poly-Q repeats. a) Helical wheel illustration for a regular heptad pattern composed built up by 21 Gln residues. The Gln residues are found in all seven (a-b-c-d-e-f-g) positions of the heptad repeat due to the particular chemical nature of this amino acid. b) Modelled structure of a canonical CC composed of 42 Gln residues. c) Structural representation of the oligomerization states driven by the supercoiling of the α-helices in a parallel orientation. d,e) Examples of functional protein-DNA and protein-protein interactions mediated by CCs. d) X-ray crystal structure of the leucine zipper Pap1 bZIP dimer bound to DNA. e) Crystal Structure of a diUb chain bound to the NEMO-UBAN domain. PDB codes are: 1GD2 and 2ZVN for d) and e), respectively