title: Characterization of the frhAGB-encoding hydrogenase from a non-methanogenic hyperthermophilic archaeon.
abstract: The F420-reducing hydrogenase has been known as a key enzyme in methanogenesis. Its homologs have been identified in non-methanogenic hyperthermophilic archaea, including Thermococcus onnurineus NA1, but neither physiological function nor biochemical properties have been reported to date. The enzyme of T. onnurineus NA1 was distinguished from those of other methanogens and the members of the family Desulfurobacteriaceae with respect to the phylogenetic distribution of the α and β subunits, organization of frhAGB genes and conservation of F420-coordinating residues. RT-qPCR and Western blot analyses revealed frhA gene is not silent but is expressed in T. onnurineus NA1 grown in the presence of sulfur, carbon monoxide, or formate. The trimeric enzyme complex was purified to homogeneity via affinity chromatography from T. onnurineus NA1 and exhibited catalytic activity toward the electron acceptors such as viologens and flavins but not the deazaflavin coenzyme F420. This is the first biochemical study on the function of the frhAGB-encoding enzyme from a non-methanogenic archaea.
authors.affiliation: Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, Ansan, South Korea.
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Jeon
authors.forename: Jae Kyu
authors.initials: JK
authors.lastname: Lim
authors.forename: Min-Sik
authors.initials: MS
authors.lastname: Kim
authors.forename: Tae-Jun
authors.initials: TJ
authors.lastname: Yang
authors.forename: Seong-Hyuk
authors.initials: SH
authors.lastname: Lee
authors.forename: Seung Seob
authors.initials: SS
authors.lastname: Bae
authors.forename: Yun Jae
authors.initials: YJ
authors.lastname: Kim
authors.forename: Sang Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Sung Gyun
authors.initials: SG
authors.lastname: Kang
authors.forename: Hyun Sook
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000465:Algorithms; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D019295:Computational Biology; D004583:Electrons; D006863:Hydrogen-Ion Concentration; D006864:Hydrogenase / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D013696:Temperature; D019712:Thermococcus / Q000201:enzymology / Q000235:genetics*
chemical_list: D019843:Archaeal Proteins; D006864:Hydrogenase