title: IbpA the small heat shock protein from Escherichia coli forms fibrils in the absence of its cochaperone IbpB.
abstract: Small heat shock proteins (sHsps) associate with aggregated proteins, changing their physical properties in such a way that chaperone mediated disaggregation becomes much more efficient. In Escherichia coli two small Hsps, IbpA and IbpB, exist. They are 48% identical at the amino acid level, yet their roles in stabilisation of protein aggregates are quite distinct. Here we analysed the biochemical properties of IbpA. We found that IbpA assembles into protofilaments which in turn form mature fibrils. Such fibrils are atypical for sHsps. Interaction of IbpA with either its cochaperone IbpB or an aggregated substrate blocks IbpA fibril formation.
authors.affiliation: Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, Gdańsk, Poland.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Ratajczak
authors.forename: Joanna
authors.initials: J
authors.lastname: Strózecka
authors.forename: Marlena
authors.initials: M
authors.lastname: Matuszewska
authors.forename: Szymon
authors.initials: S
authors.lastname: Zietkiewicz
authors.forename: Dorota
authors.initials: D
authors.lastname: Kuczyńska-Wiśnik
authors.forename: Ewa
authors.initials: E
authors.lastname: Laskowska
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Liberek
mesh_terms: D000818:Animals; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D002479:Inclusion Bodies / Q000378:metabolism*; D051379:Mice; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; C097578:IbpA protein, E coli; D018832:Molecular Chaperones