Sulfolobus acidocaldarius

The Rieske protein II (SoxF) from Sulfolobus acidocaldarius, which is part, not of a bci or b f complex, but of the SoxM oxidase complex 18), could be expressed in E. coli, both in a full-length form containing the membrane anchor and in truncated water-soluble forms 111). In contrast to the results reported for the Rieske protein from Rhodobacter sphaeroides, the Rieske cluster was more efficiently inserted into the truncated soluble forms of the protein. Incorporation of the cluster was increased threefold when the E. coli cells were subject to a heat shock (42°C for 30 min) before induction of the expression of the Rieske protein, indicating that chaperonins facilitate the correct folding of the soluble form of SoxF. The iron content of the purified soluble SoxF variant was calculated as 1.5 mol Fe/mol protein the cluster showed g values very close to those observed in the SoxM complex and a redox potential of E° = +375 mV 111). 

To date, only two exceptions to the pK of 8 rule have been found the Rieske protein from Sulfolobus acidocaldarius (139) and that from Thiobacillus ferrooxidans (140). In both cases, a first pK is observed in the vicinity of 6 (Fig. 7). The fact that Sulfolobus and Thiobacillus are phylogenetically almost as distant as they can possibly be, but share acidophilic growth conditions (medium-pH of 2), indicates that the pK, which is lower by 2 pH units in Sulfolobus and Thiobacillus, reflects adaptation. In the absence of structural information for the two acidophilic Rieske proteins, the molecular modifications resulting in this pK shift are difficult to guess. The absence of sequence data for the Thiobacillus protein furthermore precludes a comparative approach. It seems likely, however, that the solvent-exposed histidine ligands to the cluster will become slightly more bur-... 

Kargi, F., and Robinson, J. M., Microbial Oxidation of Dibenzothiophene by the Thermophilic Organism Sulfolobus Acidocaldarius. Biotechnology and Bioengineering, 1984. 26 p. 687. 

Kankipati, P., and Ju, L. K., Microbial Desulfurization of Petroleum Fundamental Study on Dibenzothiophene Desulfurization by Sulfolobus Acidocaldarius. In Exploration Issues and Solutions in Petroleum Exploration, Production and Refining. 1994. Pennwell Books. 605-614. 

In the context of the desirability of removing sulfur compounds from fuels, a bacterial strain has been identified that will metabolize thianthrene to water-soluble products under aerobic conditions (83MI5). A thermophilic organism, Sulfolobus acidocaldarius, removed 38% of the sulfur, as measured by sulfate release, in 4 weeks at 70°C (87MI2). 

Last, but by no means least, reference should be made to the use of proteins in nano-fabrication [492]. One approach is illustrated by the fabrication of a 1-nm-thick metal film with 15-nm-diameters holes, periodically arranged on a triangular protein lattice [493]. Advantage was taken of the 10-nm-thick, uniformly porous surface (or S) layer of the crystalline protein obtained from the thermophilic bacterium Sulfolobus acidocaldarius. The protein was adsorbed from a dilute solution onto a molecularly smooth carbon-film surface, metal coated by evaporation, and ion milled to give spatial ordering of holes with the same nanometer periodicity as the protein lattice [493]. 

The expression and characterization of a recombinant subunit II of the archaebacterial terminal oxidase complex in Sulfolobus acidocaldarius was achieved. The binuclear CuA centre was shown to be correctly inserted. A protonation of one of the coordinating histidines was suggested from the pH-profile.109 The subunit is part of a supercomplex SoxM which also has been isolated in a catalytically competent form for the first time.110 Nitrous oxide reductase (NOR) was prepared from Hyphomicrobium denitrificans and charac-... 

A limitation on resolution is that the desired enantiomer is only half of the racemic starting material. Kurt Faber of the University of Graz has reported (Org. Lett. 2004,6,5009) a clever solution to this problem. On exposure of the sulfate 1 of a secondary alcohol to aerobically grown whole cells of Sulfolobus acidocaldarius DSM 639, one enantiomer of the sulfate was smoothly converted into the other enantiomer of the starting alcohol. The enzyme consumed the more reactive enantiomer > 200 times more rapidly than the less reactive enantiomer. For the last bit of conversion, the of the product alcohol will of course fall. One solution to this would be to run the reaction near 50% conversion, then hydrolyze the mixture to give high product alcohol 2. Exposure of the mixture to a lipase that selectively acetylated the minor enantiomer would then polish the of 2. 

Lacher, K. Schafer, G. Archaebacterial adenylate kinase from the thermoacidophile Sulfolobus acidocaldarius purification, characterization, and partial sequence. Arch. Biochem. Biophys., 302, 391-397 (1993)... 

Backmann, J. Schafer, G. Wyns, L. Bonisch, H. Thermodynamics and kinetics of unfolding of the thermostable trimeric adenylate kinase from the archaeon Sulfolobus acidocaldarius. J. Mol. Biol., 284, 817-833 (1998)... 

Skorko, R. Osipiuk, J. Stetter, K.O. Glycogen-bound polyphosphate kinase from the archaebacterium Sulfolobus acidocaldarius. J. BacterioL, 171, 5162-5164 (1989)... 

Figure 12-30 Stereoscopic a-carbon plots of a 194-residue subunit of adenylate kinase from the archaebacterium Sulfolobus acidocaldarius with ADP (left side) and AMP (right side) bound into the active site. From Vonrheim et al.85i Courtesy of G. E. Schulz.

Denda, K., Konishi,J., Oshima, T., Date, T., and Yoshida, M. (1988). Molecular cloning of the -subunit of a possible non-FoFj type ATPsynthase from the acidothermophi-lic archaebacterium, Sulfolobus acidocaldarius. J. Biol. Chem. 263, 17251-17254. 

Working with a mutated bacterial strain, Isbister et al. (62) demonstrated a novel mechanism of aerobic oxidation of dibenzothiophene which involved the specific excision of the sulfur atom from the molecule (Figure 11). Studies with -labeled dibenzothiophene showed the release of the radioactivity into the aqueous phase and ion chromatography showed the appearence of sulfate. There was no radioactive carbon dioxide released when this microorganism was incubated with 14C-labeled dibenzothiophene. GC-MS analysis showed that the oxidation product was 2,2 -dihydroxybiphenyl. Kargi and Robinson (52) also report the release of sulfate from dibenzothiophene. This OSC served as the sole carbon and sulfur source in their cultures of the aerobic thermophile Sulfolobus acidocaldarius. 

Halobacterium salinarium Methanosarcina frisia Sulfolobus acidocaldarius Sulfolobus solfataricus... 

It was reported that the archaeon Sulfolobus acidocaldarius possessed a glycogen-bound polyphosphate kinase, which was active only as a native complex with glycogen (Skorko et al., 1989). This result is doubted by Cardona et al. (2001) who repeated the purification... 

In addition, PolyPs are most likely involved in the regulation of enzyme activities by participation in their phosphorylation. A protein phosphorylation process, using not ATP but high-polymer PolyPs, was revealed in the archae Sulfolobus acidocaldarius (Skorko, 1989). Tripolyphosphate was observed to be a phosphodonor of selective protein phosphorylation of rat liver microsomal membrane (Tsutsui, 1986). 

S. Cardona, F. Remonsellez, N. Guiliani and C. A. Jerez (2001). The glycogen-bound polyphosphate kinase from Sulfolobus acidocaldarius is actually a glycogen synthase. Appl. Environ. Microbiol., 67, 4773 1780. 

R. Skorko (1989). Polyphosphate as a source of phosphoryl group in protein modification in archebacterium Sulfolobus acidocaldarius. Biochimie, 71, 9-10. 

Life in a hot tub. An archaeon (Sulfolobus acidocaldarius) found in acidic hot springs contains a topoisomerase that catalyzes the ATP-driven introduction of positive supercoils into DNA. How might this enzyme be advantageous to this unusual organism ... 

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