The members of this family are probably all pyridoxal-phosphate-dependent aminotransferase enzymes with a variety of molecular functions. The family includes StsA Swiss:P72454, StsC Swiss:P77952 and StsS [1]. The aminotransferase activity was demonstrated for purified StsC protein as the L-glutamine:scyllo-inosose aminotransferase EC:2.6.1.50, which catalyses the first amino transfer in the biosynthesis of the streptidine subunit of streptomycin [1].

1: Identification of stsC, the gene encoding the L-glutamine:scyllo-inosose aminotransferase from streptomycin-producing Streptomycetes. Ahlert J, Distler J, Mansouri K, Piepersberg W; Arch Microbiol 1997;168:102-113. PMID:9238101