title: Expression and biochemical characterization of two small heat shock proteins from the thermoacidophilic crenarchaeon Sulfolobus tokodaii strain 7.
abstract: We expressed and characterized two sHsps, StHsp19.7 and StHsp14.0, from a thermoacidophilic crenarchaeon, Sulfolobus tokodaii strain 7. StHsp19.7 forms a filamentous structure consisting of spherical particles and lacks molecular chaperone activity. Fractionation of Sulfolobus extracts by size exclusion chromatography with immunoblotting indicates that StHsp19.7 exists as a filamentous structure in vivo. On the other hand, StHsp14.0 exists as a spherical oligomer like other sHsps. It showed molecular chaperone activity to protect thermophilic 3-isopropylmalate dehydrogenase (IPMDH) from thermal aggregation at 87 degrees C. StHsp14.0 formed variable-sized complexes with denatured IPMDH at 90 degrees C. Using StHsp14.0 labeled with fluorescence or biotin probe and magnetic separation, subunit exchanges between complexes were demonstrated. This is the first report on the filament formation of sHsp and also the high molecular chaperone activity of thermophilic archaeal sHsps.
authors.affiliation: Department of Biotechnology and Life Sciences, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Usui
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Ishii
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kawarabayasi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yohda
mesh_terms: D050539:3-Isopropylmalate Dehydrogenase; D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D001710:Biotin; D002850:Chromatography, Gel; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics; D005456:Fluorescent Dyes; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D006834:Hydrazines; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D016944:Sulfolobus / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development; D013696:Temperature
chemical_list: C417561:Alexa 488 hydrazide; D005456:Fluorescent Dyes; D006360:Heat-Shock Proteins; D006834:Hydrazines; D011994:Recombinant Proteins; D001710:Biotin; D000429:Alcohol Oxidoreductases; D050539:3-Isopropylmalate Dehydrogenase