“…34−39 BtrR, a dual functional aminotransferase for the biosynthesis of 2-DOS in butirosin, has also been biochemically and structurally characterized. 40,41 Surprisingly, limited examples were available on the biochemical and structural characterization of aminotransferases responsible for scaffold construction/modification in the biosynthesis of bacterial secondary metabolites, including OxyQ (anhydrotetracycline, in vivo studies), 42 Neo-18 (neomycin) and BtrB (butirosin), 43 PvdH (pyoverdinesiderophore), 44 YwfG (anticapsin), 45 PctV (pactamycin), 46,47 and GenS2 (gentamycin). 48 The crystal structure of PigE, 49 an aminotransferase in prodigiosin biosynthesis, 50 was recently reported.…”