Thermus thermophilus

Thecaa3-oxidase from Thermus thermophilushas been studied with a combined electrochemical, UV/VIS and Fourier-transform infrared (FT-IR) spectroscopic approach. In this oxidase the electron donor, cytochromec, is covalently bound to subunit II of the cytochrome c oxidase. Oxidative electrochemical redox titrations in the visible spectral range yielded a midpoint potential of )0.01 ± 0.01 V (vs. Ag/AgCl/3MKCl, 0.218 V vs. SHE¢) for the hemec.

9p research12 29-04-2013 49 3   Download

Random PCR mutagenesis was applied to theThermus thermophilus xylA gene encoding xylose isomerase. Three cold-adapted mutants were isolated with the following amino-acid substitutions: E372G, V379A (M-1021), E372G, F163L (M-1024) and E372G (M-1026). The wild-type and mutated xylAgenes were cloned and expressed in Escherichia coliHB101 using the vector pGEMÒ-T Easy, and their physicochemical and catalytic properties were determined.

7p research12 29-04-2013 54 3   Download

The interaction of aThermus thermophilustmRNA tran-script with alanyl-tRNA synthetase and elongation factor Tu has been studied. The synthetic tmRNA was found to be stable up to 70
C. The thermal optimum of tmRNA alanylation was determined to be around 50
C. At 50
C, tmRNA transcript was aminoacylated by alanyl-tRNA synthetase with 5.9times lower efficiency (kcat /Km) than tRNA Ala , primarily because of the difference in turnover numbers (kcat ).

13p tumor12 20-04-2013 47 3   Download

NADHoxidase fromThermus thermophilusis a homodimer with anunknownphysiological function. As is typical for an enzyme isolated froma thermophile,the catalytic rate,kcat,is low at low temperatures and increases with temperature, achieving an optimum at the physiological temperature of the organism,i.e. at
70
CforT. thermophilus.Atlow temperatures,thekcatof several enzymes from thermophilic and mesophilic organisms can be increased by chaotropic agents.

11p fptmusic 12-04-2013 34 3   Download

To probe the stability of the seven-iron ferredoxin from Thermus thermophilus(FdTt), we investigated its chemical and thermal denaturationprocesses insolution.Aspredicted from the crystal structure, FdTt is extremely resistant to perturbation. The guanidine hydrochloride-induced unfolding transition shows a midpoint at 6.5M(pH 7, 20
C), andthe thermalmidpoint is aboveboiling, at 114
C. The stability of FdTt is much lower at acidic pH, suggesting that electrostatic interactions are important for the high stability at higher pH.

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The conformational dynamics of NADH oxidase from Thermus thermophiluswas modulated by the Hofmeister series of anions (H2PO4 – ,SO4 2– ,CH3COO – ,Cl – ,Br – ,I – , ClO4 – ,SCN – ) in the concentration range 0–3M. Both cha-otropic and kosmotropic anions,at high concentration, inhibit the enzyme by different mechanisms. Chaotropic anions increase the apparent Michaelis constant and decre-ase the activation barrier of the reaction. Kosmotropic ani-ons have the opposite effect.

10p dell39 03-04-2013 39 3   Download

Horizontal gene transfer has been a major force for genome plasticity over evolutionary history, and is largely responsible for fitness-enhancing traits, including antibiotic resistance and virulence factors. In particular, for adap-tation of prokaryotes to extreme environments, lateral gene transfer seems to have played a crucial role.

9p inspiron33 25-03-2013 41 3   Download

The natural transformation system of the thermophilic bacteriumThermus thermophilus HB27 comprises at least 16 distinct competence proteins enco-ded by seven distinct loci. In this article, we present for the first time biochemical analyses of the Thermus thermophiluscompetence proteins PilMNOWQ and PilA4, and demonstrate that thepilMNOWQgenes are each essential for natural transformation.

12p inspiron33 25-03-2013 38 3   Download

At the optimal temperature (65C),Thermus thermophiluspolynucleotide phosphorylase (Tth PNPase), produced inEscherichia colicells and isolated to functional homogeneity, completely destroys RNAs that possess even a very stable intramolecular secondary structure, but leaves intact RNAs whose 3¢ end is protected by chemical modification or by hybridization with a complementary oligonucleotide.

13p media19 06-03-2013 43 3   Download

CYP175A1 fromThermus thermophilusis a thermophilic cytochrome P450 and has great potential for industrial applications. However, a native elec-tron transport system for CYP175A1 has not been identified. Here, an elec-tron transport system for CYP175A1 was isolated from T. thermophilus HB27 by multistep chromatography, and identified as comprising ferre-doxin (Fdx; locus in the genome, TTC1809) and ferredoxin–NAD(P) + reductase (FNR; locus in the genome, TTC0096) by N-terminal amino acid sequence analysis and MALDI-TOF-MS, respectively. ...

14p viettel02 22-02-2013 65 6   Download

ClpB, a member of the expanded superfamily of ATPases associated with diverse cellular activities (AAA+), forms a ring-shaped hexamer and coop-erates with the DnaK chaperone system to reactivate aggregated proteins in an ATP-dependent manner.

9p cosis54 05-01-2013 40 4   Download