<p>This entry represents subunit A, one of the three subunits of the anaerobic sulphite reductase of Salmonella, and close homologues from various Clostridium species, where the three-gene neighbourhood is preserved. Two such gene clusters are found in <taxon tax_id="1502">Clostridium perfringens</taxon>, but it may be that these sets of genes correspond to the distinct assimilatory and dissimilatory forms seen in <taxon tax_id="1501">Clostridium pasteurianum</taxon>. Note that any one of these enzymes may have secondary substrates such as NH2OH, SeO3(2-), and SO3(2-). Heterologous expression of the anaerobic sulphite reductase of Salmonella confers on <taxon tax_id="562">Escherichia coli</taxon> the ability to produce hydrogen sulphide gas from sulphite.</p> Sulphite reductase, subunit A