Query: NC_001263:72681 Deinococcus radiodurans R1 chromosome 1, complete sequence
Lineage: Deinococcus radiodurans; Deinococcus; Deinococcaceae; Deinococcales; Deinococcus-Thermus; Bacteria
General Information: This red-pigmented organism's name means "strange berry that withstands radiation", marking the fact that this organism is one of the most radiation-resistant known. It can tolerate radiation levels at 1000 times the levels that would kill a human and it was originally isolated in 1956 from a can of meat that had been irradiated with X-rays. The resistance to radiation may reflect its resistance to dessication, which also causes DNA damage. This organism may be of use in cleaning up toxic metals found at nuclear weapons production sites due to the radiation resistance. This bacterium is also a highly efficient transformer, and can readily take up exogenous DNA from the environment, which may also aid DNA repair. This organism carries multiple copies of many DNA repair genes, suggesting a robust system for dealing with DNA damage. The recombination system may rely on multiple copies of various repeat elements found throughout the genome.
Subject: NC_006396:2625962 Haloarcula marismortui ATCC 43049 chromosome I, complete sequence
Lineage: Haloarcula marismortui; Haloarcula; Halobacteriaceae; Halobacteriales; Euryarchaeota; Archaea
General Information: This organism was isolated from the Dead Sea and will provide information on the proteins necessary for adaptation to a high salt environment. Halophilic archaeon. Halobacterial species are obligately halophilic microorganisms that have adapted to optimal growth under conditions of extremely high salinity 10 times that of sea water. They contain a correspondingly high concentration of salts internally and exhibit a variety of unusual and unique molecular characteristics. Since their discovery, extreme halophiles have been studied extensively by chemists, biochemists, microbiologists, and molecular biologists to define both molecular diversity and universal features of life. A notable list of early research milestones on halophiles includes the discovery of a cell envelope composed of an S-layer glycoprotein, archaeol ether lipids and purple membrane, and metabolic and biosynthetic processes operating at saturating salinities. These early discoveries established the value of investigations directed at extremophiles and set the stage for pioneering phylogenetic studies leading to the three-domain view of life and classification of Halobacterium as a member of the archaeal domain. This organism is also know as "Halobacterium of the Dead Sea". Growth occurs in 1.7-5.1 M NaCl with optimum salt concentration of 3.4-3.9 M NaCl. The cytosol of this organism is a supersaturated salt solution in which proteins are soluble and active. This halophile is chemoorganotrophic and able to use a wide variety of compounds as sole carbon and energy sources.