MS/MS networking of Pseudoalteromonas OT59 and 04M1A and piscicida JCM 20779T. (A) MS/MS cluster of bromoalterochromide (red, orange, yellow, gray, and teal nodes are 04M1A, OT59, P. piscicida JCM 20779T, OT59/04M1A, and metabolites originating from all organisms, respectively). (B) Bromoalterochromide gene cluster. Purple, ammonia lyase; orange, type II PKS/fatty acid synthase; red, NRPS; gray, transporters; green, thioesterase; pink, halogenase; black, hypothetical proteins. (C) Proposed biosynthetic pathway with speculative double halogenation by ORF 238 after acyl chain elongation.