Fig. 4 |. TnmJ deformylates TNM I (8) to yield TNM J (13), H₂O and CO₂.

a, GC–MS results from in vitro reactions of TnmJ with TNM I (8) releases CO₂ as a byproduct. std, standard. b, The proposed mechanism for conversion of 8 to 13 by TnmJ is initiated by deprotonation of the C11-OH and a subsequent electron transfer to O₂ (i), followed by formation of a peroxide intermediate at C14 (ii) and a six-membered ring with the C16 aldehyde (iii). Collapse of the ring yields a C14-OH and C16-COO⁻ (iv), which are lost as water and CO₂, respectively, resulting in 13 (v). For a more detailed mechanism, see Supplementary Fig. 28. O₂-derived oxygens incorporated by TnmJ are highlighted in red. c, The synthetic carboxylic acid 14 was assayed with 20 μM TnmJ in vitro and compared with 8 and 1 μM TnmJ. Data are mean and s.d. (n = 3 independent experiments).