title: Dimer structure and conformational variability in the N-terminal region of an archaeal small heat shock protein, StHsp14.0.
abstract: Small heat shock proteins (sHsps), which are categorized into a class of molecular chaperones, bind and stabilize denatured proteins to prevent aggregation. The sHsps undergo transition between different oligomeric states to control their hydrophobicity. So far, only the structures of sHsps in large oligomeric states have been reported. Here we report the structure of StHsp14.0 from Sulfolobus tokodaii in the dimeric state, which is formed by means of a mutation at the C-terminal IXI/V motif. The dimer is the sole building block in two crystal forms, and the dimeric mode is the same as that in the large oligomers. The N-terminal helix has variety in its conformation. Furthermore, spectroscopic and biochemical experiments were performed to investigate the conformational variability at the N-terminus. The structural, dynamical and oligomeric properties suggest that chaperone activity of StHsp14.0 is mediated by partially dissolved oligomers.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Takeda
authors.forename: Takuro
authors.initials: T
authors.lastname: Hayashi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Abe
authors.forename: Yu
authors.initials: Y
authors.lastname: Hirano
authors.forename: Yuya
authors.initials: Y
authors.lastname: Hanazono
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yohda
authors.forename: Kunio
authors.initials: K
authors.lastname: Miki
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry* / Q000378:metabolism*; D002942:Circular Dichroism; D018360:Crystallography, X-Ray / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D050888:Heat-Shock Proteins, Small / Q000737:chemistry* / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D055503:Protein Multimerization; D017433:Protein Structure, Secondary
chemical_list: D019843:Archaeal Proteins; D050888:Heat-Shock Proteins, Small