Nat. Struct. Mol. Biol. 14, 381–387 (2007); published online 22 April 2007; corrected after print 8 May 2007

In the version of this article initially published, the incorrect corresponding authors were listed. The corresponding author should be Pingwei Li (pingwei@neo.tamu.edu). We apologize for this mistake.

In addition, a paper was not cited. The missing citation is: 49. Altschuler, E.L., Hud, N.V., Mazrimas, J.A. & Rupp, B. Random coil conformation for extended polyglutamine stretches in aqueous soluble monomeric peptides. J. Pept. Res. 50, 73–75 (1997).

The citation should appear on page 381, in the eighth sentence of the article's second paragraph, as follows: “However, studies involving polyQ peptides14,26–28,49, and our studies using polyQ tracts in the context of the HD exon 1 protein29, demonstrated that the predominant species of both normal and expanded unaggregated polyQ in solution is an extended random coil and showed no evidence for a detectable population of expanded soluble polyQ molecules with global conformational differences from normal polyQ.”

These errors have been corrected in the HTML and PDF versions of the article.