Extended Data Figure 6 |. Heterologous expression of BPSCSK LanA1–4 lantibiotic.

a, Genes involved in BP_SCSK’s lantibiotic biosynthesis (His-tagged-LanA, LanB, and LanC) were cloned into expression vectors (pRSFDuet-1/LanA+LanB, pCDFDuet- 1/LanC) and heterologously expressed in E. coli. a, a schematic map indicating where each lantibiotic gene was inserted into the respective expression vectors. b,c, the His-tagged-LanA_1–4 lantibiotic was purified from E. coli lysates by HiTrap HP nickel affinity chromatography and subsequently purified to homogeneity by reversed-phase high-performance liquid chromatography (RP-HPLC). The leader sequence and His-tag were removed by trypsin digestion to yield the mature lantibiotic. The purified His-tag product (b) and the purified mature lantibiotic (c) were analyzed by ESI-MS and the spectrum was deisotoped and deconvoluted using the Xtract algorithm in Xcalibur. The signals with labels correspond to the predicted mass of the His-tagged lantibiotic (M) and its incomplete forms that did not dehydrate all 9 residues (M + 1•H₂O, M + 2•H₂O, etc.).