Cysteine anaerobic metabolism

The cluster found in certain bacterial ferredoxins involved in anaerobic metabolism. It consists of a cubane-like cluster of four iron atoms, four labile sulphur atoms, thus Fe4S4, and four cysteine ligands... 

It is apparent from the two pathways of the anaerobic metabolism of cysteine that sulfide can be formed by either of two reactions. The reverse of this process was suggested by an experiment of Smythe and Holliday (84), who found an S -exchange between sulfide and cysteine in the presence of a liver extract. In yeast, serine sulfhydrase (86) catalyzes... 

Sulfate reduction. All plants, animals, and bacteria metabolize sulfur in order to synthesize amino acids such as cysteine and methionine. The sulfur may be assimilated as sulfate or as organic molecules containing sulfate. The reduction of sulfate in biosynthesis is termed assimilatory sulfate reduction and can take place in aerobic or anaerobic environments (cf. Goldhaber and Kaplan 1974 Rheinheimer 1981 Cullimore 1991). 

Anaerobic glucose metabolism, ketogenesis and catabolism of methionine and cysteine produce protons... 

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