PMID: 27047745

Authors:

Zhemkov VA, Kulminskaya AA, Bezprozvanny IB, Kim M

Title:

The 2.2-Angstrom resolution crystal structure of the carboxy-terminal region of ataxin-3.

Journal:

FEBS Open Bio. 2016 Feb 18;6(3):168-78. doi: 10.1002/2211-5463.12029. eCollection, 2016 Mar.

Abstract:

An expansion of polyglutamine (polyQ) sequence in ataxin-3 protein causes spinocerebellar ataxia type 3, an inherited neurodegenerative disorder. The crystal structure of the polyQ-containing carboxy-terminal fragment of human ataxin-3 was solved at 2.2-A resolution. The Atxn3 carboxy-terminal fragment including 14 glutamine residues adopts both random coil and alpha-helical conformations in the crystal structure. The polyQ sequence in alpha-helical structure is stabilized by intrahelical hydrogen bonds mediated by glutamine side chains. The intrahelical hydrogen-bond interactions between glutamine side chains along the axis of the polyQ alpha-helix stabilize the secondary structure. Analysis of this structure furthers our understanding of the polyQ-structural characteristics that likely underlie the pathogenesis of polyQ-expansion disorders.