title: Structure validation of the Josephin domain of ataxin-3: conclusive evidence for an open conformation.
abstract: The availability of new and fast tools in structure determination has led to a more than exponential growth of the number of structures solved per year. It is therefore increasingly essential to assess the accuracy of the new structures by reliable approaches able to assist validation. Here, we discuss a specific example in which the use of different complementary techniques, which include Bayesian methods and small angle scattering, resulted essential for validating the two currently available structures of the Josephin domain of ataxin-3, a protein involved in the ubiquitin/proteasome pathway and responsible for neurodegenerative spinocerebellar ataxia of type 3. Taken together, our results demonstrate that only one of the two structures is compatible with the experimental information. Based on the high precision of our refined structure, we show that Josephin contains an open cleft which could be directly implicated in the interaction with polyubiquitin chains and other partners.
authors.affiliation: National Institute for Medical Research, The Ridgeway, London, NW7 1AA, UK.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nicastro
authors.forename: Michael
authors.initials: M
authors.lastname: Habeck
authors.forename: Laura
authors.initials: L
authors.lastname: Masino
authors.forename: Dmitri I
authors.initials: DI
authors.lastname: Svergun
authors.forename: Annalisa
authors.initials: A
authors.lastname: Pastore
mesh_terms: D000067699:Ataxin-3; D001499:Bayes Theorem; D008968:Molecular Conformation; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D009687:Nuclear Proteins / Q000737:chemistry*; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021281:Quantitative Structure-Activity Relationship; D012097:Repressor Proteins / Q000737:chemistry*; D025801:Ubiquitin
chemical_list: D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; D025801:Ubiquitin; C092341:ATXN3 protein, human; D000067699:Ataxin-3