A genomic analysis of the archael system Ignicoccus hospitalis-Nanoarchaeum equitans

Journal Article · Mon Sep 01 04:00:00 EDT 2008 · Genome Biology

OSTI ID:970571

Sun, Hui; Anderson, Iain; Makarova, Kira S; Elkins, James G; Ivanova, Natalia; Wall, Mark A; Lykidis, Athanasios; Mavromatis, Konstantinos; Podar, Mircea; Hudson, Matthew E; Chen, Wenqiong; Deciu, Cosmin; Hutchinson, Don; Eads, Jonathan R; Anderson, Abraham; Fernandes, Fillipe; Szeto, Ernest; Lapidus, Alla; Kyrpides, NikosC; Saier, Jr, Milton G ; Richardson, Paul M; Rachel, Reinhard; Huber, Harald; Eisen, Jonathan A; Koonin, Eugene V; Keller, Martin; Stetter, Karl O

BACKGROUND: The relationship between the hyperthermophiles Ignicoccus hospitalis and Nanoarchaeum equitans is the only known example of a specific association between two species of Archaea. Little is known about the mechanisms that enable this relationship. RESULTS: We sequenced the complete genome of I. hospitalis and found it to be the smallest among independent, free-living organisms. A comparative genomic reconstruction suggests that the I. hospitalis lineage has lost most of the genes associated with a heterotrophic metabolism that is characteristic of most of the Crenarchaeota. A streamlined genome is also suggested by a low frequency of paralogs and fragmentation of many operons. However, this process appears to be partially balanced by lateral gene transfer from archaeal and bacterial sources. CONCLUSIONS: A combination of genomic and cellular features suggests highly efficient adaptation to the low energy yield of sulfur-hydrogen respiration and efficient inorganic carbon and nitrogen assimilation. Evidence of lateral gene exchange between N. equitans and I. hospitalis indicates that the relationship has impacted both genomes. This association is the simplest symbiotic system known to date and a unique model for studying mechanisms of interspecific relationships at the genomic and metabolic levels.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Genomics Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 970571
• Report Number(s): LBNL-2253E
• Journal Information: Genome Biology, Journal Name: Genome Biology
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CARBON
ENERGY YIELD
FRAGMENTATION
GENES
METABOLISM
NITROGEN
RESPIRATION