Hydrogenosomes of Anaerobic Ciliates At Least One Appears to Be a Missing Link

3 Hydrogenosomes of Anaerobic Ciliates At Least One Appears to Be a Missing Link 

Such a metabolism ( fumarate respiration ) is well known from anaerobic mitochondria (Tielens et al. 2002 Tielens and van Hellemond, Chap. 6 in this volume), but is unique in combination with a hydrogenase that might compete with the fumarate reductase for the same substrates. This hydrogenase of N. ovalis represents a novel type of [Fe]-only or [FeFe]-hydrogenase that allows H2 formation to be coupled directly to the reoxidation of NADH. The [Fe]-hydrogenase is linked covalently with a protein, which possesses NAD and FMN binding sites, and a ferredoxin-like FeS module that allows transfer 

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