This enzyme is also called serine deaminase. L-serine dehydratase converts serine into pyruvate in the gluconeogenesis pathway from serine. This enzyme is comprised of a single chain in <taxon tax_id="562">Escherichia coli</taxon>, <taxon tax_id="1773">Mycobacterium tuberculosis</taxon>, and several other species, but has separate alpha and beta chains in <taxon tax_id="1423">Bacillus subtilis</taxon> and related species. The beta and alpha chains are homologous to the N-terminal and C-terminal regions, respectively, but are rather deeply branched in a UPGMA tree. This enzyme requires iron and dithiothreitol for activation <i>in vitro</i>, and is a predicted 4Fe-4S protein. <taxon tax_id="562">Escherichia coli</taxon> <taxon tax_id="287">Pseudomonas aeruginosa</taxon> have two copies of this protein. Iron-sulphur-dependent L-serine dehydratase single chain form