title: Divergence of the hyperthermophilic archaea Pyrococcus furiosus and P. horikoshii inferred from complete genomic sequences.
abstract: Divergence of the hyperthermophilic Archaea, Pyrococcus furiosus and Pyrococcus horikoshii, was assessed by analysis of complete genomic sequences of both species. The average nucleotide identity between the genomic sequences is 70-75% within ORFs. The P. furiosus genome (1.908 mbp) is 170 kbp larger than the P. horikoshii genome (1.738 mbp) and the latter displays significant deletions in coding regions, including the trp, his, aro, leu-ile-val, arg, pro, cys, thr, and mal operons. P. horikoshii is auxotrophic for tryptophan and histidine and is unable to utilize maltose, unlike P. furiosus. In addition, the genomes differ considerably in gene order, displaying displacements and inversions. Six allelic intein sites are common to both Pyrococcus genomes, and two intein insertions occur in each species and not the other. The bacteria-like methylated chemotaxis proteins form a functional group in P. horikoshii, but are absent in P. furiosus. Two paralogous families of ferredoxin oxidoreductases provide evidence of gene duplication preceding the divergence of the Pyrococcus species.
authors.affiliation: The Center of Marine Biotechnology, University of Maryland Biotechnology Institute, Baltimore, Maryland 21202, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Maeder
authors.forename: R B
authors.initials: RB
authors.lastname: Weiss
authors.forename: D M
authors.initials: DM
authors.lastname: Dunn
authors.forename: J L
authors.initials: JL
authors.lastname: Cherry
authors.forename: J M
authors.initials: JM
authors.lastname: González
authors.forename: J
authors.initials: J
authors.lastname: DiRuggiero
authors.forename: F T
authors.initials: FT
authors.lastname: Robb
mesh_terms: D019843:Archaeal Proteins / Q000235:genetics; D019641:DNA, Archaeal / Q000235:genetics*; D019143:Evolution, Molecular; D019766:Genes, Archaeal; D016678:Genome; D006358:Hot Temperature; D019711:Pyrococcus / Q000235:genetics*; D020027:Pyrococcus furiosus / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D019843:Archaeal Proteins; D019641:DNA, Archaeal