title: Multi-subunit assembly of the Pyrococcus furiosus small heat shock protein is essential for cellular protection at high temperature.
abstract: The hyperthermophilic archaeon, Pyrococcus furiosus, expresses a small, alpha-crystallin-like protein in response to exposure to extreme temperatures, above 103 degrees C. The P. furiosus small heat shock protein (Pfu-sHSP) forms large oligomeric complexes. Based on the available crystal structures of the Methanocaldococcus jannaschii and wheat sHSPs, the protruding carboxy terminal domain is probably involved in subunit interactions. We constructed Pfu-sHSP mutants to analyze chaperone function and to study multi-subunit assembly. The results confirmed that the carboxy terminus of Pfu-sHSP is involved in inter-dimer interactions, whereas the amino terminal deletion mutant still exhibited the wild-type assembly characteristics. The ability to form oligomeric complexes via the carboxy terminal domain was shown to be necessary for thermotolerance of Escherichia coli overexpressing Pfu-sHSP. The amino terminal domain was not required for inter-species thermotolerance.
authors.affiliation: Center of Marine Biotechnology, University of Maryland Biotechnology Institute, 701 E Pratt St, Baltimore, MD 21202, USA.
authors.forename: P
authors.initials: P
authors.lastname: Laksanalamai
authors.forename: A
authors.initials: A
authors.lastname: Jiemjit
authors.forename: Z
authors.initials: Z
authors.lastname: Bu
authors.forename: D L
authors.initials: DL
authors.lastname: Maeder
authors.forename: F T
authors.initials: FT
authors.lastname: Robb
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D019641:DNA, Archaeal / Q000235:genetics; D019281:Dimerization; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006358:Hot Temperature; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D021122:Protein Subunits; D020027:Pyrococcus furiosus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D038201:alpha-Crystallins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D019641:DNA, Archaeal; D006360:Heat-Shock Proteins; D021122:Protein Subunits; D011994:Recombinant Proteins; D038201:alpha-Crystallins