title: The first prokaryotic trehalose synthase complex identified in the hyperthermophilic crenarchaeon Thermoproteus tenax.
abstract: The role of the disaccharide trehalose, its biosynthesis pathways and their regulation in Archaea are still ambiguous. In Thermoproteus tenax a fused trehalose-6-phosphate synthase/phosphatase (TPSP), consisting of an N-terminal trehalose-6-phosphate synthase (TPS) and a C-terminal trehalose-6-phosphate phosphatase (TPP) domain, was identified. The tpsp gene is organized in an operon with a putative glycosyltransferase (GT) and a putative mechanosensitive channel (MSC). The T. tenax TPSP exhibits high phosphatase activity, but requires activation by the co-expressed GT for bifunctional synthase-phosphatase activity. The GT mediated activation of TPS activity relies on the fusion of both, TPS and TPP domain, in the TPSP enzyme. Activation is mediated by complex-formation in vivo as indicated by yeast two-hybrid and crude extract analysis. In combination with first evidence for MSC activity the results suggest a sophisticated stress response involving TPSP, GT and MSC in T. tenax and probably in other Thermoproteales species. The monophyletic prokaryotic TPSP proteins likely originated via a single fusion event in the Bacteroidetes with subsequent horizontal gene transfers to other Bacteria and Archaea. Furthermore, evidence for the origin of eukaryotic TPSP fusions via HGT from prokaryotes and therefore a monophyletic origin of eukaryotic and prokaryotic fused TPSPs is presented. This is the first report of a prokaryotic, archaeal trehalose synthase complex exhibiting a much more simple composition than the eukaryotic complex described in yeast. Thus, complex formation and a complex-associated regulatory potential might represent a more general feature of trehalose synthesizing proteins.
authors.affiliation: Institute for Molecular and Cellular Anatomy, University of Regensburg, Regensburg, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Zaparty
authors.forename: Anna
authors.initials: A
authors.lastname: Hagemann
authors.forename: Christopher
authors.initials: C
authors.lastname: Bräsen
authors.forename: Reinhard
authors.initials: R
authors.lastname: Hensel
authors.forename: Andrei N
authors.initials: AN
authors.lastname: Lupas
authors.forename: Henner
authors.initials: H
authors.lastname: Brinkmann
authors.forename: Bettina
authors.initials: B
authors.lastname: Siebers
mesh_terms: D019843:Archaeal Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004789:Enzyme Activation; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D019848:Gene Expression Regulation, Archaeal; D022761:Gene Transfer, Horizontal; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D006358:Hot Temperature; D008969:Molecular Sequence Data; D009876:Operon; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D041542:Thermoproteus / Q000737:chemistry / Q000201:enzymology / Q000235:genetics*; D020798:Two-Hybrid System Techniques
chemical_list: D019843:Archaeal Proteins; D011994:Recombinant Proteins; D005964:Glucosyltransferases; C023180:trehalose-6-phosphate synthase; C023178:trehalose-phosphatase; D010744:Phosphoric Monoester Hydrolases