Fig. 1

Enzymes to synthesize methyl BFAs. a Mechanism of 10-methyl BFA synthesis. BfaB and TmpB utilize SAM to methylate monounsaturated phospholipid-bound fatty acids in the cell membrane. BfaA uses NADPH to reduce the 10-methylene BFA to a 10-methyl BFA, while the TmpA mechanism is unknown. b T. curvata bfaAB and M. hydrocarbonoclasticus tmpBA gene operon topology and domain conservation are depicted. BfaB and TmpB are 31% identical and share the same protein family (PF) domain with cfa, which are associated with phospholipid binding and SAM binding. BfaA and TmpA both have flavoprotein domains, but they belong to different protein families and share no meaningful protein homology. c The engineered bfaA-B and bfaB-A gene constructs used for yeast engineering. The two protein domains are fused via a 12 amino acid linker (AGGAEGGNGGGA) derived from the Y. lipolytica Fas2 protein