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Arsenite oxidase, an ancient bioenergetic enzyme?. ATPase. Electron transfer chain. H +. Hélice transmembranaire. Cluster [2Fe-2S]. Domaine soluble. arsenite oxidase from Alcaligenes faecalis. Ellis et al. 2001 Structure 9, 125-132.
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ATPase Electron transfer chain H+
Hélice transmembranaire Cluster [2Fe-2S] Domaine soluble
arsenite oxidase from Alcaligenes faecalis Ellis et al. 2001 Structure 9, 125-132
Distribution of arsenite oxidases on the phylo tree of species
Chloroflexusaurantiacus - thermophilic photosynthetic bacterium (affiliated to Thermus-group) - isolated from a Yellowstone Park hot spring - earliest branching phototroph in standard ssu rRNA-trees - genome sequenced no bc-complex in Chloroflexus (genome), sole Rieske protein in the arsenite oxidase operon Inital results: - Rieske protein is membrane-associated (no RPE signal in supernatant) - Rieske protein can be light-oxidised, i.e. electrons from AsIII oxidation enter the photosynthetic electron transfer chain
ATPase Electron transfer chain H+
- hn + AsIII ? AsV Chloroflexus in the presence of arsenite ATPase mena- quinone photo- system arsox AuCy H+
Rieske [3Fe4S] Mo cyt c Alcaligenes faecalis oxidase AsIII/ AsV Em (mV) Chloroflexus aurantiacus 0 Mo ? [3Fe4S] ? Rieske 100 AuCy ? 200 P/P+ (photosystem) 300
BIP 09/CNRS Marseile Frauke Baymann (CR1) Anne-Lise Ducluzeau (Mastère) Simon Duval (Mastère) Evelyne Lebrun (CR1) Wolfgang Nitschke (DR2) Barbara Schoepp (CR1)