title: Metagenomic mining for thermostable esterolytic enzymes uncovers a new family of bacterial esterases.
abstract: Biocatalysts exerting activity against ester bonds have a broad range of applications in modern biotechnology. Here, we have identified a new esterolytic enzyme by screening a metagenomic sample collected from a hot spring in Kamchatka, Russia. Biochemical characterization of the new esterase, termed EstDZ2, revealed that it is highly active against medium chain fatty acid esters at temperatures between 25 and 60 °C and at pH values 7-8. The new enzyme is moderately thermostable with a half-life of more than six hours at 60 °C, but exhibits exquisite stability against high concentrations of organic solvents. Phylogenetic analysis indicated that EstDZ2 is likely an Acetothermia enzyme that belongs to a new family of bacterial esterases, for which we propose the index XV. One distinctive feature of this new family, is the presence of a conserved GHSAG catalytic motif. Multiple sequence alignment, coupled with computational modelling of the three-dimensional structure of EstDZ2, revealed that the enzyme lacks the largest part of the "cap" domain, whose extended structure is characteristic for the closely related Family IV esterases. Thus, EstDZ2 appears to be distinct from known related esterolytic enzymes, both in terms of sequence characteristics, as well as in terms of three-dimensional structure.
authors.affiliation: Institute of Biology, Medicinal Chemistry &Biotechnology, National Hellenic Research Foundation, Athens, Greece.|Laboratory of Biotechnology, School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
authors.forename: Dimitra
authors.initials: D
authors.lastname: Zarafeta
authors.affiliation: Laboratory of Biotechnology, School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
authors.forename: Danai
authors.initials: D
authors.lastname: Moschidi
authors.affiliation: Laboratory of Biotechnology, School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
authors.forename: Efthymios
authors.initials: E
authors.lastname: Ladoukakis
authors.affiliation: Winogradsky Institute of Microbiology, Research Center for Biotechnology Russian Academy of Sciences, Moscow, Russian Federation.
authors.forename: Sergey
authors.initials: S
authors.lastname: Gavrilov
authors.affiliation: Institute of Biology, Medicinal Chemistry &Biotechnology, National Hellenic Research Foundation, Athens, Greece.
authors.forename: Evangelia D
authors.initials: ED
authors.lastname: Chrysina
authors.affiliation: Institute of Biology, Medicinal Chemistry &Biotechnology, National Hellenic Research Foundation, Athens, Greece.
authors.forename: Aristotelis
authors.initials: A
authors.lastname: Chatziioannou
authors.affiliation: Winogradsky Institute of Microbiology, Research Center for Biotechnology Russian Academy of Sciences, Moscow, Russian Federation.
authors.forename: Ilya
authors.initials: I
authors.lastname: Kublanov
authors.affiliation: Institute of Biology, Medicinal Chemistry &Biotechnology, National Hellenic Research Foundation, Athens, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Skretas
authors.affiliation: Laboratory of Biotechnology, School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
authors.forename: Fragiskos N
authors.initials: FN
authors.lastname: Kolisis
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D004795:Enzyme Stability; D004950:Esterases / Q000737:chemistry / Q000235:genetics; D045482:Hot Springs / Q000382:microbiology*; D056186:Metagenomics; D012800:Siberia; D014871:Water Microbiology
chemical_list: D001426:Bacterial Proteins; D004950:Esterases