title: Characterization of a multifunctional protein disulfide oxidoreductase from Sulfolobus solfataricus.
abstract: A potential role in disulfide bond formation in the intracellular proteins of thermophilic organisms has recently been ascribed to a new family of protein disulfide oxidoreductases (PDOs). We report on the characterization of SsPDO, isolated from the hyperthermophilic archaeon Sulfolobus solfataricus. SsPDO was cloned and expressed in Escherichia coli. We revealed that SsPDO is the substrate of a thioredoxin reductase in S. solfataricus (K(M) 0.3 microm) and not thioredoxins (TrxA1 and TrxA2). SsPDO/S. solfataricus thioredoxin reductase constitute a new thioredoxin system in aerobic thermophilic archaea. While redox (reductase, oxidative and isomerase) activities of SsPDO point to its central role in the biochemistry of cytoplasmic disulfide bonds, chaperone activities also on an endogenous substrate suggest a potential role in the stabilization of intracellular proteins. Northern and western analysis have been performed in order to analyze the response to the oxidative stress.
authors.affiliation: Istituto di Biostrutture e Bioimmagini, C.N.R., Naples, Italy.
authors.forename: Emilia
authors.initials: E
authors.lastname: Pedone
authors.forename: Danila
authors.initials: D
authors.lastname: Limauro
authors.forename: Romina
authors.initials: R
authors.lastname: D'Alterio
authors.forename: Mosè
authors.initials: M
authors.lastname: Rossi
authors.forename: Simonetta
authors.initials: S
authors.lastname: Bartolucci
mesh_terms: D000595:Amino Acid Sequence; D003545:Cysteine / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism; D008969:Molecular Sequence Data; D011490:Protein Disulfide Reductase (Glutathione) / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D016415:Sequence Alignment; D048229:Sulfolobus solfataricus / Q000201:enzymology*; D013997:Time Factors
chemical_list: D004220:Disulfides; D005456:Fluorescent Dyes; D018832:Molecular Chaperones; D011490:Protein Disulfide Reductase (Glutathione); D003545:Cysteine