FIG 5.
Halogenation reactions catalyzed by OrfA. (A) The OrfA-mediated halogenation reactions were conducted with the supplementation of KF, KCl, KBr, or KI, whereby only reactions supplemented with KCl or KBr can produce the corresponding product. (B) LC-MS traces for the in vitro assays conducted in the presence of OrfA alongside Fre or inactive Fre. Fre was inactivated by heating for 10 min at 95°C. (C) LC-MS traces for the production of bromoalbofungin (compound 3) in S. albus J1074::ermE*-crpSC_pmk01ΔorfA::orfA, the orfA-complement strain, with 0.02% or 0.2% KBr. (D) The LC traces of the in vitro reaction of OrfA with FADH2, O2, and KCl or KBr. (E) MS spectrum of compound 3.