title: Analysis of the complete genome of Fervidococcus fontis confirms the distinct phylogenetic position of the order Fervidicoccales and suggests its environmental function.
abstract: The complete genome of the obligately anaerobic crenarchaeote Fervidicoccus fontis Kam940(T), a terrestrial hot spring inhabitant with a growth optimum of 65-70 °C, has been sequenced and analyzed. The small 1.3-Mb genome encodes several extracellular proteases and no other extracellular hydrolases. No complete pathways of carbohydrate catabolism were found. Genes coding for enzymes necessary for amino acid transamination and further oxidative decarboxylation are present. The genome encodes no mechanisms of acyl-CoA and acetyl-CoA oxidation. Two [NiFe]-hydrogenases are encoded: a membrane-bound energy-converting hydrogenase and a cytoplasmic one. The ATP-synthase is H(+)-dependent as inferred from the amino acid sequence of the membrane rotor subunit. On the whole, genome analysis shows F. fontis to be a peptidolytic heterotroph with a restricted biosynthetic potential, which is in accordance with its phenotypic properties. The analysis of phylogenetic markers and of the distribution of best blastp hits of F. fontis proteins in the available genomes of Crenarchaeota supports distinct phylogenetic position of the order Fervidicoccales as a separate lineage adjoining the heterogeneous order Desulfurococcales. In addition, certain F. fontis genomic features correlate with its adaptation to temperatures of 60-80 °C, which are lower than temperatures preferred by Desulfurococcales.
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospekt 60-let Oktyabrya, 7/2, Moscow, 117312, Russia, a.lebedinsky@mail.ru.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Lebedinsky
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Mardanov
authors.forename: Ilya V
authors.initials: IV
authors.lastname: Kublanov
authors.forename: Vadim M
authors.initials: VM
authors.lastname: Gumerov
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Beletsky
authors.forename: Anna A
authors.initials: AA
authors.lastname: Perevalova
authors.forename: Salima Kh
authors.initials: SKh
authors.lastname: Bidzhieva
authors.forename: Elizaveta A
authors.initials: EA
authors.lastname: Bonch-Osmolovskaya
authors.forename: Konstantin G
authors.initials: KG
authors.lastname: Skryabin
authors.forename: Nikolai V
authors.initials: NV
authors.lastname: Ravin
mesh_terms: D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D019615:Crenarchaeota / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D004777:Environment; D020745:Genome, Archaeal; D053858:Metabolic Networks and Pathways; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D019843:Archaeal Proteins