Archaea Genomes - THERMOCOCCUS KODAKARAENSIS

T. kodakaraensis, is one of the organisms closest to the last common ancestor of all life, they are of scientific interest to understand the origin of life and its early evolution.

T. kodakaraensis, KOD1 was isolated from a solfatara (a vent which emits sulphorous gases) on Kodakara Island, Japan. It had previously been reported as Pyrococcus sp. KOD1, however a detailed phylogenetic tree, made possible by the recent accumulation of 16S rRNA sequences of various species in the order Thermococcales, indicated that strain KOD1 is a member of the genus Thermococcus and that strain KOD1 represents a new species of Thermococcus, which was designated as Thermococcus kodakaraensis KOD1 sp. nov.

The genus Thermococcus, comprises sulfur-reducing hyperthermophilic archaea. Thermococcus are ubiquitously present in natural high-temperature environments, and are therefore considered to play a major role in the ecology and metabolic activity of microbial consortia within hot-water ecosystems.

To obtain insight into this important genus, we have determined and annotated the complete 2,088,737-base genome of , followed by a comparison with the three complete genomes of Pyrococcus spp

Comparative genomics between Thermococcus kodakaraensis strain KOD1 and three Pyrococcus spp strains clarified that 1204 proteins, including those for information processing and basic metabolisms, are shared although among the set of 689 proteins unique to T. kodakaraensis, there are several intriguing proteins that might be responsible for the specific trait of the genus Thermococcus, such as proteins involved in additional pyruvate oxidation, nucleotide metabolisms, unique or additional metal ion transporters, improved stress response system, and a distinct restriction system.

References:

http://www.genome.org/cgi/content/short/gr.3003105v1
http://archaea.ws/archive/summaries/volume1/a1-263.html
http://www.sbchem.kyoto-u.ac.jp/english/laboratory/biochemical/biochemical.htm