title: A novel trehalose synthesizing pathway in the hyperthermophilic Crenarchaeon Thermoproteus tenax: the unidirectional TreT pathway.
abstract: In the genome of the hyperthermophilic archaeon Thermoproteus tenax a gene (treS/P) encoding a protein with similarity to annotated trehalose phosphorylase (TreP), trehalose synthase (TreS) and more recently characterized trehalose glycosyltransferring synthase (TreT) was identified. The treS/P gene as well as an upstream located ORF of unknown function (orfY) were cloned, heterologously expressed in E. coli and purified. The enzymatic characterization of the putative TreS/P revealed TreT activity. However, contrary to the previously characterized reversible TreT from Thermococcus litoralis and Pyrococcus horikoshii, the T. tenax enzyme is unidirectional and catalyzes only the formation of trehalose from UDP (ADP)-glucose and glucose. The T. tenax enzyme differs from the reversible TreT of T. litoralis by its preference for UDP-glucose as co-substrate. Phylogenetic and comparative gene context analyses reveal a conserved organization of the unidirectional TreT and OrfY gene cluster that is present in many Archaea and a few Bacteria. In contrast, the reversible TreT pathway seems to be restricted to only a few archaeal (e.g. Thermococcales) and bacterial (Thermotogales) members. Here we present a new pathway exclusively involved in trehalose synthesis--the unidirectional TreT pathway--and discuss its physiological role as well as its phylogenetic distribution.
authors.affiliation: Department of Chemistry, Biofilm Centre, Molecular Enzyme Technology and Biochemistry, University of Duisburg-Essen, Lotharstr., MF Building, 47057 Duisburg, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Kouril
authors.forename: Melanie
authors.initials: M
authors.lastname: Zaparty
authors.forename: Jeannette
authors.initials: J
authors.lastname: Marrero
authors.forename: Henner
authors.initials: H
authors.lastname: Brinkmann
authors.forename: Bettina
authors.initials: B
authors.lastname: Siebers
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D019976:Cloning, Organism; D019766:Genes, Archaeal; D005947:Glucose / Q000378:metabolism; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010783:Photometry; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D041542:Thermoproteus / Q000201:enzymology* / Q000235:genetics; D014199:Trehalose / Q000378:metabolism*
chemical_list: D019843:Archaeal Proteins; D011994:Recombinant Proteins; D014199:Trehalose; D005964:Glucosyltransferases; C099692:trehalose synthase; C023181:alpha,alpha-trehalose phosphorylase; D005947:Glucose