Pre_GI: SWBIT SVG BLASTP

Query: NC_010674:426256 Clostridium botulinum B str. Eklund 17B, complete genome

Lineage: Clostridium botulinum; Clostridium; Clostridiaceae; Clostridiales; Firmicutes; Bacteria

General Information: Clostridium botulinum B str. Eklund 17B is a nonproteolytic botulism neurotoxin B strain. This strain was isolated from marine sediments taken off the coast of Washington, USA and was not associated with botulism. This genus comprises about 150 metabolically diverse species of anaerobes that are ubiquitous in virtually all anoxic habitats where organic compounds are present, including soils, aquatic sediments and the intestinal tracts of animals and humans. This shape is attributed to the presence of endospores that develop under conditions unfavorable for vegetative growth and distend single cells terminally or sub-terminally. Spores germinate under conditions favorable for vegetative growth, such as anaerobiosis and presence of organic substrates. It is believed that present day Mollicutes (Eubacteria) have evolved regressively (i.e., by genome reduction) from gram-positive clostridia-like ancestors with a low GC content in DNA. This organism produces one of the most potent and deadly neurotoxins known, a botulinum toxin that prevents the release of acetylcholine at the neuromuscular junction, thereby inhibiting muscle contraction and causing paralysis. In most cases the diseased person dies of asphyxiation as a result of paralysis of chest muscles involved in breathing. The spores are heat-resistant and can survive in inadequately heated, prepared, or processed foods. Spores germinate under favorable conditions (anaerobiosis and substrate-rich environment) and bacteria start propagating very rapidly, producing the toxin.Botulinum toxin, and C. botulinum cells, has been found in a wide variety of foods, including canned ones. Almost any food that has a high pH (above 4.6) can support growth of the bacterium. Honey is the most common vehicle for infection in infants. Food poisoning through C. botulinum is the most frequent type of infection caused by this bacterium. The wound botulism that occurs when C. botulinum infects an individual via an open wound is much rarer and is very similar to tetanus disease. There are several types of botulinum toxin known (type A through type F), all of them being neurotoxic polypeptides. The most common and widely distributed are strains and serovars of C. botulinum that produce type A toxin.

Subject: NC_006396:1097000 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.