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Pendants les années 1997 et 1998, un groupe des chercheurs de SFB 268 a effectué, dans la région de l’Atakora, des recherches botaniques, ethnologiques et géographiques concernant l’histoire du peuplement. Les travaux étaient concentrés sur la partie ouest de la région, c’est-à-dire le triangle Boukombé, Natitingou, Toucountouna. En résultat, il est possible aujourd’hui de faire une chronologie relative à l’histoire du peuplement dans cette région. En contraire, il manque toujours une chronologie absolue, pour cela il faut encore des recherches approfondies. Pourtant nous allons proposer, dans le cours de cette contribution, des hypothèses montrant le cadre, dans lequel une périodisation peut être possible.
We analyzed a eukaryotically encoded rubredoxin from the cryptomonad Guillardia theta and identified additional domains at the N- and C-termini in comparison to known prokaryotic paralogous molecules. The cryptophytic N-terminal extension was shown to be a transit peptide for intracellular targeting of the protein to the plastid, whereas a C-terminal domain represents a membrane anchor. Rubredoxin was identified in all tested phototrophic eukaryotes. Presumably facilitated by its C-terminal extension, nucleomorph-encoded rubredoxin (nmRub) is associated with the thylakoid membrane. Association with photosystem II (PSII) was demonstrated by co-localization of nmRub and PSII membrane particles and PSII core complexes and confirmed by comparative electron paramagnetic resonance measurements. The midpoint potential of nmRub was determined as +125 mV, which is the highest redox potential of all known rubredoxins. Therefore, nmRub provides a striking example of the ability of the protein environment to tune the redox potentials of metal sites, allowing for evolutionary adaption in specific electron transport systems, as for example that coupled to the PSII pathway.