IbpA the small heat shock protein from Escherichia coli forms fibrils in the absence of its cochaperone IbpB.
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.
Ratajczak
Elzbieta
E
Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, Gdańsk, Poland.
Strózecka
Joanna
J
Matuszewska
Marlena
M
Zietkiewicz
Szymon
S
Kuczyńska-Wiśnik
Dorota
D
Laskowska
Ewa
E
Liberek
Krzysztof
K
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
D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; C097578:IbpA protein, E coli; D018832:Molecular Chaperones