| Item type: | Article | ||||
|---|---|---|---|---|---|
| Journal or Publication Title: | Journal of Bacteriology | ||||
| Publisher: | AMER SOC MICROBIOLOGY | ||||
| Place of Publication: | WASHINGTON | ||||
| Volume: | 201 | ||||
| Number of Issue or Book Chapter: | 7 | ||||
| Date: | 2019 | ||||
| Institutions: | Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Mikrobiologie (Archaeenzentrum) Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Mikrobiologie (Archaeenzentrum) > Prof. Dr. Dina Grohmann | ||||
| Identification Number: |
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| Keywords: | NANOARCHAEUM-EQUITANS; MEMBRANE-PROTEIN; OUTER-MEMBRANE; SP-NOV; ARCHAEA; HOSPITALIS; ARCHAEBACTERIUM; COMPLEXES; ION; MECHANISM; ATP synthase; ATPase; Archaea; Crenarchaea; Ignicoccus; bioenergetics; protein purification; protein stability | ||||
| Dewey Decimal Classification: | 500 Science > 570 Life sciences | ||||
| Status: | Published | ||||
| Refereed: | Yes, this version has been refereed | ||||
| Created at the University of Regensburg: | Yes | ||||
| Item ID: | 48847 |
Web of ScienceAbstract
In this study, the ATP synthase of Ignicoccus hospitalis was purified, characterized, and structurally compared to the respective enzymes of the other Ignicoccus species, to shed light on energy conservation in this unique group of archaea. The crenarchaeal genus Ignicoccus comprises three described species, i.e., I. hospitalis and Ignicoccus islandicus from hot marine sediments near Iceland and ...
Abstract
In this study, the ATP synthase of Ignicoccus hospitalis was purified, characterized, and structurally compared to the respective enzymes of the other Ignicoccus species, to shed light on energy conservation in this unique group of archaea. The crenarchaeal genus Ignicoccus comprises three described species, i.e., I. hospitalis and Ignicoccus islandicus from hot marine sediments near Iceland and Ignicoccus pacificus from a hydrothermal vent system in the Pacific Ocean. This genus is unique among all archaea due to the unusual cell envelope, consisting of two membranes that enclose a large intermembrane compartment (IMC). I. hospitalis is the best studied member of this genus, mainly because it is the only known host for the potentially parasitic archaeon Nanoarchaeum equitans. I. hospitalis grows chemolithoautotrophically, and its sole energy-yielding reaction is the reduction of elemental sulfur with molecular hydrogen, forming large amounts of hydrogen sulfide. This reaction generates an electrochemical gradient, which is used by the ATP synthase, located in the outer cellular membrane, to generate ATP inside the IMC. The genome of I. hospitalis encodes nine subunits of an A-type ATP synthase, which we could identify in the purified complex. Although the maximal in vitro activity of the I. hospitalis enzyme was measured around pH 6, the optimal stability of the A(1)A(O) complex seemed to be at pH 9. Interestingly, the soluble A(1) subcomplexes of the different Ignicoccus species exhibited significant differences in their apparent molecular masses in native electrophoresis, although their behaviors in gel filtration and chromatography-mass spectrometry were very similar. IMPORTANCE The Crenarchaeota represent one of the major phyla within the Archaea domain. This study describes the successful purification of a crenarchaeal ATP synthase. To date, all information about A-type ATP synthases is from euryarchaeal enzymes. The fact that it has not been possible to purify this enzyme complex from a member of the Crenarchaeota until now points to significant differences in stability, possibly caused by structural alterations. Furthermore, the study subject I. hospitalis has a particular importance among crenarchaeotes, since it is the only known host of N. equitans. The energy metabolism in this system is still poorly understood, and our results can help elucidate the unique relationship between these two microbes.
Metadata last modified: 03 Sep 2021 10:03
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