title: Genome Sequencing ofSulfolobussp. A20 from Costa Rica and Comparative Analyses of the Putative Pathways of Carbon, Nitrogen, and Sulfur Metabolism in VariousSulfolobusStrains.
abstract: The genome ofSulfolobussp. A20 isolated from a hot spring in Costa Rica was sequenced. This circular genome of the strain is 2,688,317 bp in size and 34.8% in G+C content, and contains 2591 open reading frames (ORFs). Strain A20 shares ~95.6% identity at the 16S rRNA gene sequence level and <30% DNA-DNA hybridization (DDH) values with the most closely related knownSulfolobusspecies (i.e.,Sulfolobus islandicusandSulfolobus solfataricus), suggesting that it represents a novelSulfolobusspecies. Comparison of the genome of strain A20 with those of the type strains ofS. solfataricus, Sulfolobus acidocaldarius, S. islandicus, andSulfolobus tokodaii, which were isolated from geographically separated areas, identified 1801 genes conserved among allSulfolobusspecies analyzed (core genes). Comparative genome analyses show that central carbon metabolism inSulfolobusis highly conserved, and enzymes involved in the Entner-Doudoroff pathway, the tricarboxylic acid cycle and the CO2fixation pathways are predominantly encoded by the core genes. AllSulfolobusspecies encode genes required for the conversion of ammonium into glutamate/glutamine. SomeSulfolobusstrains have gained the ability to utilize additional nitrogen source such as nitrate (i.e.,S. islandicusstrain REY15A, LAL14/1, M14.25, and M16.27) or urea (i.e.,S. islandicusHEV10/4,S. tokodaiistrain7, andS. metallicusDSM 6482). The strategies for sulfur metabolism are most diverse and least understood.S. tokodaiiencodes sulfur oxygenase/reductase (SOR), whereas bothS. islandicusandS. solfataricuscontain genes for sulfur reductase (SRE). However, neither SOR nor SRE genes exist in the genome of strain A20, raising the possibility that an unknown pathway for the utilization of elemental sulfur may be present in the strain. The ability ofSulfolobusto utilize nitrate or sulfur is encoded by a gene cluster flanked by IS elements or their remnants. These clusters appear to have become fixed at a specific genomic site in some strains and lost in other strains during the course of evolution. The versatility in nitrogen and sulfur metabolism may represent adaptation ofSulfolobusto thriving in different habitats.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of SciencesBeijing, China; College of Life Sciences, University of Chinese Academy of SciencesBeijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of SciencesBeijing, China; College of Life Sciences, University of Chinese Academy of SciencesBeijing, China.
authors.forename: Haina
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences Beijing, China.
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences Beijing, China.
authors.forename: Kuan
authors.initials: K
authors.lastname: Li
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences Beijing, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Center for Research in Cell and Molecular Biology, Universidad de Costa Rica San José, Costa Rica.
authors.forename: Marielos
authors.initials: M
authors.lastname: Mora-López
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences Beijing, China.
authors.forename: Chengying
authors.initials: C
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of SciencesBeijing, China; College of Life Sciences, University of Chinese Academy of SciencesBeijing, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences Beijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences Beijing, China.
authors.forename: Yaxin
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Center for Research in Cell and Molecular Biology, Universidad de Costa Rica San José, Costa Rica.
authors.forename: Walter
authors.initials: W
authors.lastname: Hernández-Ascencio
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences Beijing, China.
authors.forename: Zhiyang
authors.initials: Z
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of SciencesBeijing, China; College of Life Sciences, University of Chinese Academy of SciencesBeijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Huang
keywords: Sulfolobus; carbon metabolism; comparative genomics; genome sequencing; nitrogen metabolism; strain A20; sulfur metabolism