Bioenergetics
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Bioenergetics of the Archaea. [Microbiol Mol Biol Rev. 1999]
In the late 1970s, on the basis of rRNA phylogeny, Archaea (archaebacteria) was identified as a distinct domain of life besides Bacteria (eubacteria) and Eucarya. Though forming a separate domain, Archaea display an enormous diversity of lifestyles and metabolic capabilities. Many archaeal species are adapted to extreme environments with respect to salinity, temperatures around the boiling point of water, and/or extremely alkaline or acidic pH. This has posed the challenge of studying the molecular and mechanistic bases on which these organisms can cope with such adverse conditions. This review considers our cumulative knowledge on archaeal mechanisms of primary energy conservation, in relationship to those of bacteria and eucarya. Although the universal principle of chemiosmotic energy conservation also holds for Archaea, distinct features have been discovered with respect to novel ion-transducing, membrane-residing protein complexes and the use of novel cofactors in bioenergetics of methanogenesis. From aerobically respiring Archaea, unusual electron-transporting supercomplexes could be isolated and functionally resolved, and a proposal on the organization of archaeal electron transport chains has been presented. The unique functions of archaeal rhodopsins as sensory systems and as proton or chloride pumps have been elucidated on the basis of recent structural information on the atomic scale. Whereas components of methanogenesis and of phototrophic energy transduction in halobacteria appear to be unique to Archaea, respiratory complexes and the ATP synthase exhibit some chimeric features with respect to their evolutionary origin. Nevertheless, archaeal ATP synthases are to be considered distinct members of this family of secondary energy transducers. A major challenge to future investigations is the development of archaeal genetic transformation systems, in order to gain access to the regulation of bioenergetic systems and to overproducers of archaeal membrane proteins as a prerequisite for their crystallization.
Schafer G, Engelhard M, Muller V. Bioenergetics of the Archaea. (Free Full Text Article) Microbiol Mol Biol Rev. 1999 Sep;63(3):570-620.
Related Links
On the origin of respiration: electron transport proteins from archaea to man. [FEMS Microbiol Rev. 1996] PMID: 8639327
Stress genes and proteins in the archaea. [Microbiol Mol Biol Rev. 1999] PMID: 10585970
Bioenergetics of the archaebacterium Sulfolobus. [Biochim Biophys Acta. 1996] PMID: 8982385
Bioenergetics of archaea: ATP synthesis under harsh environmental conditions. [J Mol Microbiol Biotechnol. 2005] PMID: 16645313
Respiratory chains of archaea and extremophiles. [Biochim Biophys Acta. 1996] PMID: 8688447 See all Related Articles...
Gene cluster of Rhodothermus marinus high-potential iron-sulfur Protein: oxygen
A novel scenario for the evolution of haem-copper oxygen reductases. [Biochim Biophys Acta. 2001] PMID: 11334784
New genes encoding subunits of a cytochrome bc1-analogous complex in the respiratory chain of the hyperthermoacidophilic crenarchaeon Sulfolobus acidocaldarius. [J Bioenerg Biomembr. 2003] PMID: 12887010
Evolution of the cytochrome c oxidase proton pump. [J Mol Evol. 1998] PMID: 9545462
See all Related Articles...
Bioenergetics of the Archaea. [Microbiol Mol Biol Rev. 1999]
In the late 1970s, on the basis of rRNA phylogeny, Archaea (archaebacteria) was identified as a distinct domain of life besides Bacteria (eubacteria) and Eucarya. Though forming a separate domain, Archaea display an enormous diversity of lifestyles and metabolic capabilities. Many archaeal species are adapted to extreme environments with respect to salinity, temperatures around the boiling point of water, and/or extremely alkaline or acidic pH. This has posed the challenge of studying the molecular and mechanistic bases on which these organisms can cope with such adverse conditions. This review considers our cumulative knowledge on archaeal mechanisms of primary energy conservation, in relationship to those of bacteria and eucarya. Although the universal principle of chemiosmotic energy conservation also holds for Archaea, distinct features have been discovered with respect to novel ion-transducing, membrane-residing protein complexes and the use of novel cofactors in bioenergetics of methanogenesis. From aerobically respiring Archaea, unusual electron-transporting supercomplexes could be isolated and functionally resolved, and a proposal on the organization of archaeal electron transport chains has been presented. The unique functions of archaeal rhodopsins as sensory systems and as proton or chloride pumps have been elucidated on the basis of recent structural information on the atomic scale. Whereas components of methanogenesis and of phototrophic energy transduction in halobacteria appear to be unique to Archaea, respiratory complexes and the ATP synthase exhibit some chimeric features with respect to their evolutionary origin. Nevertheless, archaeal ATP synthases are to be considered distinct members of this family of secondary energy transducers. A major challenge to future investigations is the development of archaeal genetic transformation systems, in order to gain access to the regulation of bioenergetic systems and to overproducers of archaeal membrane proteins as a prerequisite for their crystallization.
Schafer G, Engelhard M, Muller V. Bioenergetics of the Archaea. (Free Full Text Article) Microbiol Mol Biol Rev. 1999 Sep;63(3):570-620.
Related Links
On the origin of respiration: electron transport proteins from archaea to man. [FEMS Microbiol Rev. 1996] PMID: 8639327
Stress genes and proteins in the archaea. [Microbiol Mol Biol Rev. 1999] PMID: 10585970
Bioenergetics of the archaebacterium Sulfolobus. [Biochim Biophys Acta. 1996] PMID: 8982385
Bioenergetics of archaea: ATP synthesis under harsh environmental conditions. [J Mol Microbiol Biotechnol. 2005] PMID: 16645313
Respiratory chains of archaea and extremophiles. [Biochim Biophys Acta. 1996] PMID: 8688447 See all Related Articles...
Gene cluster of Rhodothermus marinus high-potential iron-sulfur Protein: oxygen
A novel scenario for the evolution of haem-copper oxygen reductases. [Biochim Biophys Acta. 2001] PMID: 11334784
New genes encoding subunits of a cytochrome bc1-analogous complex in the respiratory chain of the hyperthermoacidophilic crenarchaeon Sulfolobus acidocaldarius. [J Bioenerg Biomembr. 2003] PMID: 12887010
Evolution of the cytochrome c oxidase proton pump. [J Mol Evol. 1998] PMID: 9545462
See all Related Articles...
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