Helix and turn populations of the polyQ peptides.

The helical content is partitioned into - and -helix populations. The structures are also categorized based on the number of their helical segments. The population of each category (0,1,2,) is given if greater than %. The turn content is partitioned based on both the hydrogen-bonding and turn types. For the secondary structure prediction, the DSSP analysis code [58], [59] was used along with the protocols discussed in Methods.