Thermus thermophiles

In chimeric isopropylmalate dehydrogenase from an extreme thermophile, Thermus thermophile, and a mesophile. Bacillus subtilis, the stability of each chimeric enzyme was also proportional to the content of the amino acid sequence from the T. thermophile enzyme (26). The thermal stability of the chimeras was also intermediate between that of the highly labile Type II hexokinase and the relatively stable Type I isozyme (57). 

Yokoyama, A., G. Sandmann, T. Hoshino, K. Adachi, M. Sakai, and Y. Shizuri. 1995. Thermozeaxanthins, new carotenoid-glycoside-esters from thermophilic eubacterium Thermus thermophilus. Tetrahedron Lett. 36 4901 1904. 

Littlechild, J.A. Davies, G.J. Gamblin, S.J. Watson, H.C. Phosphoglycerate kinase from the extreme thermophile Thermus thermophilus. Crystallization and preliminary X-ray data. FEBS Lett., 225, 123-126 (1987)... 

Yaklichkin, S.Y. Zimina, M.S. Neumyvakin, L.V, Proline biosynthesis gene proB of thermophilic bacterium Thermus ruber cloning, sequencing, and properties of encoded y-glutamylphosphate kinase. Mol. Biol., 33, 628-635 (1999)... 

Rather similar ribonucleotide reductases have been isolated from the thermophile, Thermus aquaticus (MW = 80 000) and Anabaena (a blue-green alga) (MW=72 000). The latter enzyme has an absolute requirement for divalent metal cations. The diphosphate reductase from Corynebacterium has a molecular weight of 200 000 and is made up of two subunits. Other enzymes appear to have tetrameric structures.817... 

Aqualysin I is an alkaline serine protease, extracellularly secreted by Thermus aquaticus YT-1,14) an extremely thermophilic, Gram-negative bacterium. The enzyme is thermostable. Optimum temperature for the proteolytic activity of aqualysin I is 80° C in the presence of 1 mM Ca2+ and 70°C in its absence (Fig. 12.1).l5) 85% of the original activity remains after treatment at 80°C for 3 h in the presence of 1 mM Ca2+, but only about 20% remains in its absence.15) These results indicate that calcium ion is essential for the structural stability of the enzyme. 

The polymerase chain reaction uses (1) a thermostable DNA polymerase, such as Taq polymerase derived from the bacterial thermophile Thermus aquaticus, (2) a DNA template which is to be amplified, (3) two primers, each typically of around 20 nucleotides, which anneal to distinct parts on the complementary strands of the target and serve as sites for commencing DNA polymerase action, (4) a solution including the four deoxynucleoside triphosphates dATP, dCTP, dGTP and dTTP, Mg2+, salts and pH buffer. 

Repeated cycles of heat denaturation, primer annealing, and enzymatic synthesis specifically increase the amount of target sequences up to 10 -fold after approximately 20-40 cycles. A recent modification of the technique has incorporated the DNA polymerase of the thermophilic bacterium, Thermus aouaticus. which resists heat inactivation during the denaturation cycles (42). The PCR technique, although quite simple in theory, will undoubtedly improve the potential sensitivity of NAHA for a variety of pathogens. 

The heat-stable DNA polymerase (Taq) commonly used in PCR reactions was isolated from a thermophilic bacterium, Thermus aquaticus. Since this enzyme is heat-stable, it can withstand the high temperatures required to denature the DNA template after each successive round of polymerization... 

Kato R, Hasegawa K, Hidaka Y, Kuramitsu S, Hoshino T (1997) Characterization of a Thermostable DNA Photolyase from an Extremely Thermophilic Bacterium, Thermus thermophilus HB27,/. Bacterial. 179, No. 

The DNA polymerase enzyme can now extend the primers and complete the replication of the rest of the DNA. The enzyme used in PCR is derived from the thermophilic bacterium Thermus aquaticus, which grows naturally in hot springs at a temperature of 90 °C, so is not denatured by the high temperatures in step 2. Its optimum temperature is about 72 °C, so the mixture is heated to this temperature for a few minutes to allow replication to take place as quickly as possible. 

Thermophilic Term nsed to describe an organism that grows at elevated temperatnres. The most famons thermophilic orgaiusm is the bacteria (Thermus aquaticus) responsible for TAQ polymerase, which is used in the PCR. See Friedman,... 

Thermophilic heterotrophic nitrifiers, capable of oxidizing NH3 to N02, were isolated from several hydrothermal vent habitats (Mevel and Prieur, 1998). Most of the isolates were N03 reducers or denitrifiers and exhibited a wide diversity related to the genera Thermus and Bacillus. Because they are able to ammonify, nitrify and reduce N03, they would seem to possess most of the physiologies of importance in the N cycle. Such organisms may be common in mesophilic aquatic habitats, but have not been quantitatively investigated. 

Kirino H, Aoki M, Aoshima M, Hayashi Y, Ohba M, Yamagishi A, Wakagi T, Oshima T. Hydrophobic interaction at the subunit 30. interface contributes to the thermostability of 3-isopropyhnalate dehydrogenase from an extreme thermophile, Thermus ther-mophilus. Eur. J. Biochem. 1994 220 275-281. 31. 

Data are from references [89,91,92] and from Mikulik (personal communication) for Calderobacterium hydrogenophilum. Reverse gyrase activity has not been detected in moderately thermophilic and mesophilic eubacteria from the genera Bacillus and Thermus [89]. In all cells lacking reverse gyrase activity, except Halobacterium halobium, one can detect an ATP-independent relaxation activity. 

PCR was initially carried out manually in incubators of different temperatures for each step until the extraction of DNA polymerase from thermophilic bacteria. The bacterium Thermus aquaticus was found in Yellow Stone National Park. This bacterium lives in the hot springs at 203°F (95°C). The DNA polymerase from T. aquaticus keeps its activity at above 95°C for many hours. Several additional heat-resistant DNA polymerases have also now been identified. 

Thermophile High temperature Moderate thermophiles (45-65°C) Thermophiles (65-85°C) Hyperthermophiles (>85°C) Amylases, xylanases Proteases, DNA polymerases Methanobacterium, Thermoplasma, Thermus, some Bacillus species, Aquifes, Archaec lobus, Hydrogenobacter, Methanothermus, Pyrococcus, Pyrodictium, Pyrolobus, Sulfolobus, Thermococcus, Thermoproteus, Thermotoga ... 

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