The biosynthesis of L-cysteine is the predominant way by which inorganic sulphur is incorporated into organic compounds. In this process, the most abundant
utilizable source of sulphur, inorganic sulphate, is taken up and reduced to sulphide. Sulphide is used to produce L-cysteine, which serves for protein synthesis or the
production of other sulphur-containing organic compounds. Two routes for cysteine biosynthesis in nature have been documented.
Serine transacetylase (EC:2.3.1.30) catalyzes steps in pathway I, the activation of L-serine by acetyl-coenzyme A, yielding O-acetyl-L-serine.
Olsen LR, Huang B, Vetting MW, Roderick SL.
Structure of serine acetyltransferase in complexes with CoA and its cysteine feedback inhibitor.
Biochemistry 43 2004 6013-9
[PubMed: 15147185] http://dx.doi.org/10.1021/bi0358521