title: Role of the N-terminal region of the crenarchaeal sHsp, StHsp14.0, in thermal-induced disassembly of the complex and molecular chaperone activity.
abstract: Small heat shock protein is a ubiquitous molecular chaperone, which consists of a non-conserved N-terminal region followed by a conserved alpha-crystallin domain. To understand the role of the N-terminal region, we constructed N-terminal truncation mutants of StHsp14.0, the sHsp from Sulfolobus tokodaii strain 7. All the mutants formed a stable oligomeric complex similar to that of the wild type. Electron microscopy and size exclusion chromatography-multiangle light scattering showed that the N-terminal region should locate in the center of the oligomeric particle. The mutants exhibited reduced chaperone activity for the protection of 3-isopropylmalate dehydrogenase from thermal aggregation. This reduction correlates with lowered subunit exchange efficiency. The oligomeric structure was retained even after incubation at 90 degrees C. These results suggest that the N-terminal region of StHsp14.0 functions in the thermally induced disassembly of the complex.
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, Tokyo 184-8588, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Usui
authors.forename: Omer Faruk
authors.initials: OF
authors.lastname: Hatipoglu
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Ishii
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yohda
mesh_terms: D050539:3-Isopropylmalate Dehydrogenase; D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D004355:Drug Stability; D017353:Gene Deletion; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D008027:Light; D008854:Microscopy, Electron; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D008970:Molecular Weight; D021122:Protein Subunits; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence; D016944:Sulfolobus / Q000737:chemistry*; D013696:Temperature; D016963:Thermus thermophilus / Q000201:enzymology
chemical_list: D019843:Archaeal Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D021122:Protein Subunits; D011994:Recombinant Proteins; D000429:Alcohol Oxidoreductases; D050539:3-Isopropylmalate Dehydrogenase