title: Polyglutamine tract binding protein-1 is an intrinsically unstructured protein.
abstract: Polyglutamine tract binding protein-1 (PQBP-1) is a nuclear protein that interacts with disease proteins containing expanded polyglutamine repeats. PQBP-1 also interacts with RNA polymerase II and a spliceosomal protein U5-15kD. In the present study, we demonstrate that PQBP-1 is composed of a large unstructured region and a small folded core. Intriguingly, the large unstructured region encompasses two functional domains: a polar amino acid rich domain and a C-terminal domain. These findings suggest that PQBP-1 belongs to the family of intrinsically unstructured/disordered proteins. Furthermore, the binding of the target molecule U5-15kD induces only minor conformational changes into PQBP-1. Our results suggest that PQBP-1 includes high content of unstructured regions in the C-terminal domain, in spite of the binding of U5-15kD.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Toyama, 2630, Sugitani, Toyama 930-0194, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Mineyuki
authors.initials: M
authors.lastname: Mizuguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shinoda
authors.forename: Tomoyasu
authors.initials: T
authors.lastname: Aizawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Demura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okazawa
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawano
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D002850:Chromatography, Gel; D002942:Circular Dichroism; D004268:DNA-Binding Proteins; D006868:Hydrolysis; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D020349:Surface Plasmon Resonance
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C119246:PQBP1 protein, human