Dokumentenart: | Artikel | ||||
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Titel eines Journals oder einer Zeitschrift: | Antonie van Leeuwenhoek | ||||
Verlag: | SPRINGER | ||||
Ort der Veröffentlichung: | DORDRECHT | ||||
Band: | 102 | ||||
Nummer des Zeitschriftenheftes oder des Kapitels: | 2 | ||||
Seitenbereich: | S. 203-219 | ||||
Datum: | 2012 | ||||
Institutionen: | Biologie und Vorklinische Medizin > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Mikrobiologie (Archaeenzentrum) > Prof. Dr. Reinhard Rachel | ||||
Identifikationsnummer: |
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Stichwörter / Keywords: | NANOARCHAEUM-EQUITANS; ARCHAEON IGNICOCCUS; OUTER-MEMBRANE; PYROCOCCUS-FURIOSUS; ELECTRON-MICROSCOPY; SP-NOV; ULTRASTRUCTURE; PROTEINS; INSIGHTS; SYSTEM; Ignicoccus hospitalis; Cell biology; Archaea; ATP synthase; Cell compartimentation; Immuno-localization; Nanoarchaeum equitans | ||||
Dewey-Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik > 570 Biowissenschaften, Biologie | ||||
Status: | Veröffentlicht | ||||
Begutachtet: | Ja, diese Version wurde begutachtet | ||||
An der Universität Regensburg entstanden: | Ja | ||||
Dokumenten-ID: | 63524 |
Zusammenfassung
The Crenarchaeon Ignicoccus hospitalis is an anaerobic, obligate chemolithoautotrophic hyperthermophile, growing by reduction of elemental sulfur using molecular hydrogen as electron donor. Together with Nanoarchaeum equitans it forms a unique, archaeal biocoenosis, in which I. hospitalis serves as host for N. equitans. Both organisms can be cultivated in a stable coculture which is mandatory for ...
Zusammenfassung
The Crenarchaeon Ignicoccus hospitalis is an anaerobic, obligate chemolithoautotrophic hyperthermophile, growing by reduction of elemental sulfur using molecular hydrogen as electron donor. Together with Nanoarchaeum equitans it forms a unique, archaeal biocoenosis, in which I. hospitalis serves as host for N. equitans. Both organisms can be cultivated in a stable coculture which is mandatory for N. equitans but not for I. hospitalis. This strong dependence is affirmed by the fact that N. equitans obtains its lipids and amino acids from the host. I. hospitalis cells exhibit several unique features: they can adhere to surfaces by extracellular appendages ('fibers') which are not used for motility; they use a novel CO2 fixation pathway, the dicarboxylate/4-hydroxybutyrate pathway; and they exhibit a unique cell envelope for Archaea consisting of two membranes but lacking an S-layer. These membranes form two cell compartments, a tightly packed cytoplasm surrounded by a weakly staining intermembrane compartment (IMC) with a variable width from 20 to 1,000 nm. In this IMC, many round or elongated vesicles are found which may function as carriers of lipids or proteins out of the cytoplasm. Based on immuno-EM analyses and immuno-fluorescence experiments it was demonstrated recently that the A(1)A(O) ATP synthase, the H-2:sulfur oxidoreductase complex and the acetyl-CoA synthetase (ACS) of I. hospitalis are located in its outermost membrane. Therefore, this membrane is energized and is here renamed as "outer cellular membrane" (OCM). Among all prokaryotes possessing two membranes in their cell envelope, I. hospitalis is the first organism with an energized outermost membrane and ATP synthesis outside the cytoplasm. Since DNA and ribosomes are localized in the cytoplasm, energy conservation is separated from information processing and protein biosynthesis in I. hospitalis. This raises questions concerning the function and characterization of the two membranes, the two cell compartments and of a possible ATP transfer to N. equitans.
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