Complete genome analysis and development of gene disruption technology in the hyperthermophilic archaeon, Thermococcus kodakaraensis

Here we describe recent progress on our studies on the hyperthermophilic archaeon, Thermococcus kodakaraensis. The complete genome sequence has been determined, revealing the presence of 2,306 genes on the chromosome. We have also developed a system that allows us to disrupt genes in a specific manner, which is the first of its kind in hyperthermophiles. The system has been improved, and it is now possible to isolate strains with multiple gene disruptions. We have utilized this technology to examine gene function in vivo. In one case, between two proteins that displayed frucose 1,6-bisphosphatase in vitro, we have been able to determine the physiologically relevant protein in T. kodakaraensis. In another study, we were able to examine a mutant strain deprived of the reverse gyrase gene, the one and only hyperthermophile-specific gene.